... Output Speed Reducer Worm Gearbox Reducer 2.Model:RV030,Ratio:7.5-100 NMRV030 Ratio 1:7. ... 5-1:100 Aluminium Double Extension Worm Shaft with Flange Output Speed ... and durable(6) Stable transmission, quiet operation(7) High heat-radiating efficiency, high carrying ability(8 ... tested before sendingSpecifiction: Type:Worm Gear Speed ReducerModel:NMRV030Ratio:7.5,10,15,20,25,30, ...