Specially-modified high-performance 351mm-long and 3mm-wide drive belt. This gear is quite slim and elastic as you are able to for an exceptionally effective transmission that considerably reduces friction and helps to reduce battery pack draw. The belt is particularly hand ground on a special machine for minimal depth and flexibility, without impacting lifespan. To fully benefit from the benefits from these superior belts, be sure all transmission ball-bearings are positively clean to cut back drag and friction.