3-jaw insert design is complete with keyway and set screw. No lubrication required. This listing is for each. Technical Specification Item - Jaw Coupling Hubs Jaw Coupling Hub Size - Jaw Couplings FC25 Bore Dia. 1 in Keyway Size Type 1/4 in x 1/8 in Material - Hubs Steel Outside Dia. 2.5 in Assembled Coupling Length 4.13 in Overall Length 4.13 in WARNING Cancer and Reproductive Harm -