Suggest to add lubricating oil, it can be reduce the friction between the metal gears, also the sound will be smaller when it is running.

Compatible with Redcat Lightning EPX Drift, Lightning EPX PRO, Sandstorm, Sandstorm TK, Tsunami EPX, Volcano Epx/epx PRO, Vortex HSP 1/10 Monster Truck;also compatible with HSP 94107 94111 94123 94170 1/10 RC Car
Made of high quality metal material,strong and durable in use.
Easy to install and upgrade your rc car.

Item Name: Differential Main Gear & Pinion Gear
Material: Metal
Main Gear:64T;Pinion Gear:17T 21T 26T 29T ;
Main Gear hole inner diameter:5mm;
Pinion Gear Hole Inner Diameter:3.17mm

Motor Gear Height: Approx. 11mm
Main Gear:Approx. 9mm

64T Main Gear Diameter: Approx. 40mm/1.6in
17T Diameter: Approx. 11.5mm
21T Diameter: Approx.14mm
26T Diameter: Approx.16.5mm
29T Diameter: Approx.18.5mm

Package List:
1 x 64T Spur Gear
1 x 17T Motor Gear
1 x 21T Motor Gear
1 x 26T Motor Gear
1 x 29T Motor Gear