This hub has a 15mm bore, 5mm keyway, 56.0mm OD, and 12.0mm length.
Ruland supplied Controlflex couplings are a lightweight, low inertia, and zero-backlash coupling designed for use in encoders, tachometers, resolvers, and light duty power transmission applications. It has a balanced design and can accommodate speeds of up to 10000 RPM. The use of a keyway prevents the coupling from slipping on the shaft if over torqued.