Girth (tack) slightly too small, a girth extender may be used. A girth extender attaches to the billets of the saddle and lengthens them, so that a shorter girth may be used. Most jumping saddles have three billets. This not only allows the rider a spare should one break, but can also provide an adjustment option. For horses on which the saddle sits nicely, neither slipping forward or back, the first and third billets should be used. On horses where the saddle slips back, the first and second billets should be used. The second and third should never be used together, as
Harness saddle shafts from beneath. For display, a saddle pad may be placed beneath the saddle; historically in England a saddle pad, also called "housing" or "saddle cloth", was shaped to match the contour of the saddle, in the manner of an English numnah today. For heavy use, the saddle may be six or more inches long, front to back. For very light use, saddle and girth may be replaced by a surcingle. The harness saddle has at least two lines of evolution, both departures from the very ancient throat-and-girth harness . One line was developed as a refinement of that harness