It has 17mm x 16mm bores, 5mm x 5mm keyways, 50.8mm OD, and 58.7mm length.
8mm, L 58. Ruland standard length bellows couplings are a high torque zero-backlash coupling commonly found in responsive systems on semiconductor, solar, test and measurement, and printing equipment. Keyed Clamp Bellows Cplg, Bores 17x16mm, OD 50. The bellows are able to flex while remaining rigid under torsional loads allowing for all types of misalignment to be accommodated.