This Martin Quadra-Flex coupling sleeve is for use on specific Martin flange types (J type flanges in the case of JEM and JEMS type sleeves, and all flange types in the case of EM type sleeves) in the Quadra-Flex series flexible coupling assemblies. It is made of thermoplastic rubber for resistance to oil and an operating temperature range of -50 to 275 degrees F (-46 to 135 degrees C). This Quadra-Flex coupling sleeve comes in three types: one-piece solid (Type JEM), one-piece split (Type JEMS), and two-piece split with a metal retaining ring (Type EM) for applications where the coupled shafts separate. Martin Quadra-Flex couplings are suitable for applications that require torsional flexibility and the capacity to withstand shock loads and vibration, including blowers, compressors, conveyors, dredges, feeders, generators, mills, and presses, among others.

Flexible couplings are used to link two rotating shafts that are not aligned in order to transmit the rotational power, known as torque, from one shaft to the other. Most flexible couplings consist of two hubs and a middle assembly; each hub attaches to a shaft while the middle assembly flexes between the hubs to accommodate the misalignment of the two shafts. Shaft misalignments are generally either parallel or angular and cause complications to transmitting rotational power from one shaft to another in the form of stresses, loads, vibrations, and other forces, which vary from one type of misalignment to another. Flexible couplings are used in a broad range of applications, such as in motor vehicles, conveyors, escalators, agricultural, forestry and mining equipment, aeronautics, robotics and space exploration, among others.

Martin Sprocket & Gear manufactures power transmission and conveying products. Martin provides tools that meet American National Standards Institute (ANSI), National Aerospace Standard (NAS), and Deutsches Institut für Normung (DIN) standards. The company, founded in 1951, is headquartered in Arlington, TX.