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
Tree girth measurement the measurement description [17] The height of this measurement point above the standard base point at midslope should also be noted. If measuring a mountaintop forest of stunted trees only six feet tall, a girth measurement made at 4.5 feet would be meaningless. In the case of these stunted trees a girth taken at 1-foot above the base might be more appropriate. The point is that the girth measurements should be taken at the standard heights whenever possible. Where this measurement is not meaningful, an additional girth measurement should be taken at a more appropriate position and that height noted.