Every model has a continuously adjustable gullet system. You are able to change it yourself: A small hole in the front of the saddle is intended for a 10 mm Allen Wrench. By rotating it, the gullet width can be adjusted very precisely. This makes your saddle adaptable to the withers area of your horse at all times. Whether your horse develops more muscles or gains weight during summertime – this saddle goes along with all changes. The gullet system is adjustable from K1 - K5, which is comparable to the Sprenger Measuring System for Withers sizes 6 - 2.