Breeching is essentially part of the braking system for the harness. It is fitted around the rear end of the horse. As the horse slows, it uses the breeching to provide a means with which to hold the vehicle from running on.
Breeching is not generally used on leader horses (in tandem or team), as this function is taken care of by the wheeler horses. Some drivers also choose not to use breeching where the vehicle is very light and/or has very efficient braking systems - particularly on modern vehicles with disk brakes.
The Brun breeching is a heavy duty style with double hip straps for improved stability. The smooth and padded breeching seat is 80mm (3 1/2") wide. Hip straps on the Cob Size breeching are 19mm (3/4") wide, whilst the Full Size hip straps are 25mm (1") wide.