After an energetic ride you may notice an unequal sweat pattern. This could indicate there is an area where the saddle is not equally distributing the weight, causing unequal pressure on the animal's back. You can add or subtract felt shims to help alleviate the pressure, creating a more comfortable ride for your horse. The Pressure Relief Pad has a durable cotton duck top with 1" Wool felt bottom. The pockets contain 1/2" Wool felt shims, which can be removed to better fit your saddle.