878-7831, RS PRO, RS PRO Steel 40 Teeth Spur Gear, 0.5 Module, 4mm Bore Diam, 20mm Pitch Diam, 9mm Hub Diam, Brand RS Pro, Module 0.5, Number Of Teeth 40, Material Steel RS PRO Steel 40 Teeth Spur Gear, 0.5 Module, 4mm Bore Diam, 20mm Pitch Diam, 9mm Hub Diam