Product Description Low Noise Small Nmrv Worm Gearbox Reducer From CHINAMFG Product Description 1.Model Number RV 25 30 40 50 63 75 90 110 130 150 NRV No 30 40 50 63 75 90 110 130 150 2.Materials Materials Housing: HT250 cast iron Gear: 20CrMnTi,carburizing and quenching Gear surface hardness: 58-62HRC Gear center hardness: 33-48HRC … Continue reading China Hot selling Low Noise Small Nmrv Worm Gearbox Reducer From CHINAMFG