Matrix Ortho-Impact Inserts are most suitable for general riding and training, especially beneficial for horses who have some deficits in their back muscles, uneven muscle development or a saddle that does not fit perfectly. Designed to go inside the Matrix Competition Pad. A 5mm layer of ultra-thin, ultra-light XRD® bonded to 12mm layer of medium density viscoelastic foam provides the impact protection of the XRD with the additional stabilizing support of the viscoelastic foam. XRD is an ultra-light and ultra-thin layer (5mm) of high density open cell foam that absorbs 90% of the energy from impact. It protects the horse's back muscles from the impact of the saddle and minimizes the energy bounce back that the rider experiences when landing in the saddle, allowing for a more secure seat. Superior to heavier and thicker foams and gels. The 12mm viscoelastic foam will fill in deficits and allows the saddle to settle and stabilize for maximum cushioning without restricting range of motion. Sold as a pair. For Matrix Competition Cross Country Pads (see Item #27-6305, 27-7305, or 27-8305).