The high-precision BK Series of bellows couplings from R+W, a German company, are used to connect shafts up to 180 mm in diameter. The torsionally rigid couplings transmit torque with angular exactness and zero backlash. The flexible bellows compensate for misaligned shafts in the axial, angular, and lateral directions. The couplings have low moment of inertia and can handle torques between 15 and 10,000 Nm. They also work in temperatures from 30 to 120C. A key feature of the coupling is its two-piece design. It lets technicians install them in 20% of the time needed to put one-piece couplings into service. Maintenance and disassembly are also simplified. And the connection between the driving and driven side is self-adjusting and electrical and thermally insulated.