... gearbox CE,RoHS compliant 13,17.5,21.5,26Kgf-cm torque reduction ratio:from1/3.4 to 1/1975 28mm ... : gearbox length(mm)stadgereduction ratio 34.1 3.4,3.8,4.4,5.3,6.742.7 12,13,15 ... ,1304,1556,1975 28mm Low noise Planetary gearbox 13~26Kgf-cm CE RoHS