The Lonex Helical gear set comes with a spiral Bevel and Pinion gear combo that will work with most aftermarket gear brands and ratios (generally AEG 13:1 - 26:1 sets and all TM Recoil sets).
The spiral cut to these gears allow the teeth to more gradually merge together. This allows for a much smoother mesh in the most important position in the gearbox which reduces the noise generated and increases efficiency.
Contrary to other brands of helical gears, these are easy to shim. We do recommend bushings or very high quality bearings along with shimming the motor armature or pairing them with the Kingdom of Airsoft Blueprinted motors for the best results.