This pad features Orthoimpact Impact Protection and shim saddle adjustment. Choose Ortho for advanced protection using a combination of Poron XRD which absorbs up to 90% of impact, and mediun-density viscoelastic memory foam, which provides superior musculoskeletal cushioning. The Matrix Western Shim Pad has three interior pockets for shims to adapt the fit of the Western saddle to the horses conformation. Strategically place the shims to balance the saddle from front to back or adjust from side to side to compensate for asymmetrical muscle development. Easily converts from a built up to a bridge pad for use on multiple horses. Each pad comes with a set of 12 shims: 2 front, 2 middle and 2 rear for each side.