37mm 1:10 1:19 1:30 1:56 1:90 1:131 1:168 DC Motor Reducer Reducing Gear Box for 520 528 3530 3540 545 540 550 555 3429 Motor

reduction ratio:1:10 1:19 1:30 1:56 1:90 1:131 1:168 1:270 1:506 1:810

Fits for 2.0mm 3.0mm 3.17mm Shaft Motor (Please Choose the right size you need) 

Package Content:Reducing Box x 1