1:3.71 1:5.18 Dual Axis Planet Gear Speed-up Gearbox Double Shaft PLS36 also Used as Speed Reducer This is 36mm diameter gearbox, we also have 42mm, 56mm and so on. if desire other model, contact us.The planetary gearbox can increase or decrease the output speed. You can favor the product that suits you according to your personal needs.This link is for tools ratio Stage1(1:3.71, 1:5.18) we even have different ratio from 1:3.71 to 1:100, if need other equipment ratio, order other link or touch us.The maximum instant may perhaps speed up to 25,000 rpm, But it is strongly recommended that the maximum output pace within 10,000 rpm, The data of the rate increaser:Installation dimension:The first photograph is for tools ratio of 5.18, 27, 139.(One finish Shaft Diameter is 8mm-Milling edge 1mm, and the alternative finish Shaft Diameter is 6mm-Milling edge 1mm).L=29mmThe moment photo is for tools ratio of alternative besides of 5.18/27/139.(Both ends Shaft Diameter are 8mm-Milling edge 1mm)L=31mmThe label faces the output shaft of the speed increaser., and the increaser can be used as a reducer in reverse. Gearbox Double Shaft*1