The Mattes Quilt Correction Half Pad has four pockets, two in front and two in back, to hold Poly-Flex® shims that can be inserted to customize the way a saddle sits on a horse. A full set of Poly-Flex shims is included with the pad: six front and six back. Only 5mm thick, each shim can be layered or trimmed for desired results. With the assistance and recommendation of a qualified saddle fitter, shims can help adjust the fit of a saddle on an asymmetrical horse or help fit a saddle that may sit a little low or may be slightly too big. Shims or inserts will not help the fit of a saddle that is too tight, and in fact can make the tight fit worse. This low-profile half-pad style pairs light flannel on the underside and a quilted, heavy cotton top. This pad can be machine washed with MELP® and air dried. Remove shims prior to washing.