The changeable gullet bars come in two sizes:
The shorter S-Bar to fit the lower-headed trees with shorter points and a square cantle, with the exception of the Low Wither GP, which has a round cantle.
The longer R-Bar to fit the high-headed trees with long points and a round cantle (NOTE: The S-Series Jump saddle takes an R-Bar despite having a square cantle).
R-Bars are not available in Extra Extra Wide fitting
