GWS Spur Gears for EPS-400C Drives (for 4.0 mm drive shaft). GWS Spur Gears for EPS-400C Drives (for 4.0 mm drive shaft). Gear Type Spur Gear Pinion Gear Gear Ratio A M0.4x60T M0.4*28T 60T/28T=2.14 B M0.4x62T M0.4*26T 62T/26T=2.38 C M0.4x64T M0.4*24T 64T/24T=2.67 D M0.4x66T M0.4*22T 66T/22T=3.00 E M0.4x68T M0.4*20T 68T/20T=3.40 F M0.4x70T M0.4*18T 70T/18T=3.90 G M0.4x72T M0.4*16T 72T/16T=4.50 H M0.4x74T M0.4*14T 74T/14T=5.28 I M0.4x76T M0.4*12T 76T/12T=6.33