Circular
Connectors

For over 75 years, LEMO has been designing and manufacturing industry-leading precision connectors for sectors as varied as medical, test and measurement, security and defence, energy and industrial, semiconductor, broadcasting, motorsport, transportation as well as many other specialties.

Our product range runs to over 90,000 combinations of configurable connectors for high and low voltage, coaxial, thermocouple, fluidic, fibre optic and hybrid applications. The range continues to grow as we develop custom designs to meet the challenges of a rapidly changing technological world. Today, LEMO offers exceptional reliability and high-performance connectors for industries which demand evermore stringent technical and environmental specifications.

Explore our range

of high-performance circular connectors

LEMO offers a comprehensive portfolio of circular connectors, each engineered to address specific technical challenges. From miniature single-contact solutions to complex hybrid configurations, our products are built on a foundation of quality and performance. The core of our offering is the modular design, which allows you to specify the ideal configuration for your application, ensuring a perfect fit for your electrical and mechanical requirements. We provide a vast array of contact types, including electrical, coaxial, fibre optic, and fluidic, which can be combined to create a truly integrated interface.

Meet our 5 circular connector families:

ORIGINALS Your configurable solution	REDEL Your trusted medical solution	OPTIMA Your optimised solution	SUPREME Your extreme solution	SPECIALTIES Your specialised solution
Self-Latching Push-Pull locking Wide & modular range Broad application reach Indoor & outdoor	Medical and Industrial grade plastic Device ergonomics Electrical safety High density & modularity	Compact & miniature Lightweight & low-profile High vibration resistance IP68 & MIL-STD tested	High/Low pressure Radiation & corrosion High Voltage Regulated environments	Industry standards Special configurations Historical products
B - Indoor keyed LEMO original Push-Pull solution for protected environments	REDEL P - Push-Pull Highly configurable plastic Push-Pull connector	M - Rugged Ratchet coupling LEMO lightweight, compact, high vibration resistant (Mil STD 202 & 810F), IP68 screw locking connector	N - Nuclear Stainless Steel Flawless performances in highly regulated environments such as nuclear hot cells	3K.93C.Y - SMPTE Hybrid The standard for high-definition TV (SMPTE 304). Robust hybrid fiber optic connector guarenteeing certified signal integrity.
K - Outdoor keyed LEMO original Push-Pull solution for outdoor environments	REDEL SP - Inner Push-Pull Highly configurable plastic connector with inner Push-Pull	F - Rugged Push-Pull LEMO lightweight, compact, high vibration resistant (Mil STD 810F), IP67 Push-Pull connector	W - Underwater High water pressure screw locking connectors designed for demanding marine and underwater applications	00 - NIM-CAMAC LEMO original Push-Pull solution for protected environments
T - Indoor keyed LEMO original miniature Push-Pull solution for outdoor environments	REDEL MP - Modular Inner Push-Pull Modular plastic connectors	D - Rugged Miniature Push-Pull LEMO compact and miniature, high vibration resistance (Mil STD 810H), IP68 Push-Pull connector	Y - High Voltage Unipole Single contact high voltage connectors in high grade materials	Other specialities Learn more
S - Indoor keyed LEMO original Push-Pull solution with unmatched mating ergonomy
E - Indoor keyed LEMO original Push-Pull solution for outdoor environments with unmatched mating ergonomy

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Signature push-pull systems for secure and rapid mating

At the heart of the LEMO experience is our original, patented push-pull self-latching system. This mechanism provides an exceptionally secure and reliable connection that is impossible to disconnect accidentally. A simple axial pull on the outer shell is all that is required to disengage the plug from the socket, making it ideal for applications where space is limited and ease of use is paramount.
This rapid mating and de-mating process significantly reduces installation and maintenance time without compromising the integrity of the connection. The system provides clear tactile and audible feedback upon successful mating, giving you complete confidence in the security of your wiring and cable assembly. For a classic example of this industry-defining technology, you can explore the original LEMO B Series, which remains a benchmark for performance and reliability.

Learn more about our Locking System

Miniature, high-density, and custom-engineered solutions

Modern electronic systems demand increasing functionality within smaller footprints. LEMO excels in developing miniature (50 Ohms) and high-density circular connectors that help you overcome space and weight constraints without sacrificing performance. Our engineering expertise allows for a high number of contacts to be housed in a very compact connector body, enabling you to reduce the size of your equipment while increasing its capabilities.
When off-the-shelf solutions do not meet your exact specification, our teams are ready to collaborate. We are not just a component supplier; we are your technical partner. We work with you to develop custom-engineered connectors tailored to your unique application, from modified designs to completely new solutions. This collaborative approach ensures that every aspect of the connector—from the contact configuration and material selection to the specific coupling mechanism—is optimised for your system. To see the breadth of our tailored capabilities, review our portfolio of specialised connector solutions.

Modular, Compact and High Density Circular Connectors

The LEMO advantage:
reliability and precision engineered

Choosing a LEMO connector is an investment in your system's long-term performance. Our reputation is built upon a deep-rooted commitment to Swiss engineering principles, where precision and quality are not merely objectives, but fundamental requirements. This ethos is embedded in every stage of our process, from initial design and material sourcing to automated manufacturing and rigorous quality control. The result is a connector that you can depend on, even when failure is not an option.

Swiss-made quality delivering unmatched system dependability

Every LEMO connector is a product of meticulous design and manufacturing. We control the entire production chain, ensuring that every component meets our stringent quality standards. This vertical integration allows for unparalleled consistency and traceability.

Key features that ensure this level of dependability include:

High-endurance contacts:

Our electrical contacts are gold-plated to ensure superior conductivity and resistance to corrosion, guaranteeing thousands of mating cycles without performance degradation.

LEMO Circular Connector - Swiss Engineering Precision

Precision-machined housings

Connector bodies are machined from premium-grade materials like brass, stainless steel, and aluminium, providing exceptional mechanical strength and durability.

Controlled manufacturing processes:

We employ state-of-the-art automation and inspection technologies to maintain tight tolerances and ensure every connector that leaves our facility is flawless.

Designed for robust performance in harsh environments

LEMO connectors are engineered to operate reliably in the most demanding conditions. Whether your application involves extreme temperatures, high shock and vibration, or exposure to fluids and radiation, or even underwater and high water pressure environments, we have a solution designed to withstand the challenge. Our connectors offer a range of sealing options, achieving ratings up to IP68 for complete protection against dust and water ingress when mated — ensuring dependable performance even during submersion or high-pressure washdowns.
The inherent robustness of our designs ensures that the electrical interface remains stable and secure, preventing signal loss or system failure. For applications requiring extreme ruggedness and 360° electromagnetic compatibility (EMC) shielding, we developed solutions like the ultra-rugged Supreme Series, built to perform in the planet's most extreme environments. This focus on durability translates directly into lower maintenance requirements and a longer operational life for your equipment.

Harsh Environment Connectors

Trusted circular connectors across key industries

For over 75 years, professionals in critical industries have relied on LEMO to provide the connectivity solutions they need to innovate and operate safely. Our connectors are integral components in thousands of applications where performance and reliability are non-negotiable. We understand the unique standards and challenges of your industry and have developed specific product ranges to meet them.

Advancing medical, test & measurement, and broadcast technologies

In the medical field, reliability can be a matter of life and death. Our connectors are used in a wide range of devices, from diagnostic imaging systems (endoscopes, x-ray, magnetic resonance imaging, computed tomography, ultrasound, positron emission tomography) to surgical tools (life support such as ventilators, defibrillators and dialysis machines). Sterilisable and lightweight solutions, such as our REDEL P series of plastic medical connectors, are trusted by leading medical equipment manufacturers for their safety and high performance.
The Test & Measurement industry demands connectors that provide precise, repeatable, and high-fidelity signal transmission. LEMO connectors are the standard for data acquisition systems, sensors, and analytical instruments, non-destructive where signal integrity is crucial for accurate data. For applications demanding high bandwidth and immunity to interference, our hybrid electrical-fibre optic OPTIMA connectors provide a robust and reliable solution.

Enabling critical systems in defence, aerospace, and robotics

In the defence and aerospace sectors, equipment must perform flawlessly under extreme environmental and mechanical stress. Our connectors are specified for use in avionics, communications systems, unmanned aerial vehicles (UAVs), and soldier-worn equipment (Get insights from our Defence and Security Industry brochure), where robustness and weight reduction are critical design drivers. The secure locking system and high resistance to shock and vibration ensure that system connectivity is maintained during critical missions. Connectors are tested to mil standards such as EIA and MIL-STD. LEMO offers various connectors answering to SPE, Ethernet (RJ45 alternatives), and USB (Know more with our High-Speed Connectors catalogue ).
From industrial automation to advanced robotics, our circular connectors provide the reliable power (Explore our M Series catalogue) and signal interface required for complex machinery. The durability and high mating cycle life of our products are essential for applications involving constant movement and environmental exposure, helping to minimise downtime and improve overall operational efficiency.

With over 75 years of excellence and innovation, the LEMO Group is proud to be a global leader in custom high-performance interconnection solutions. From the deepest oceans to the farthest reaches of space, our solutions consistently meet the highest standards of performance and reliability.

Discover all the industries we serve.

Start Your Project with a LEMO Expert

Your next innovation deserves a connector that guarantees performance and reliability.

To discuss the specific requirements of your application or to request a custom design, we invite you to connect with our team of experienced engineers.

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