A type of axle bearing used in some Pearl kick drum pedals. NiNja Bearings are made by Performance Skate products in Japan, and were originally designed for skateboards. The bearings are super-hardened, microfinished, and sorted to eliminate high-velocity spin wobble and friction. NiNja Bearings surpass ABEC (Annular Bearing Engineers Committee) and JIS (Japanese Industrial Standards, a part of the Japanese Standards Association) standards for tolerances and performance. With kick drum pedals, NiNja Bearings are intended to provide smooth and fast pedal action.