4 GEAR MECHANISMGear Tooth Profile: involute Curve function: involute Gear Ratio:1,2,3,4 Module: 2mm True involute curves Ready to print Ready to any manufacturing processes Thanks to spiral profile; *Reliable transmission ideal for high-speed, high-torque applications *Prevents the gears from slipping *Minimizes backlash. Contact me for revision or similar designs request.