Worm Gearbox Reducer Reduction Ratio 5:1 To 80:1 For 57mm Frame NEMA23 Stepper Motor 11mm Shaft Diameter For Nema 23 Stepper Motor ,Easy to Install

Rabbet:38mm diagonal Screw hole distance:67mm Gearing Arrangement: Worm Package including: 1pcs worm gear reducer NMRV030