Magpul Industries Ladder Rail Panel, Fits Carbine Length Picatinny Rail, 18 Slots, Polymer Construction, Black MAG013-BLK Ladder Panels offer very low-profile 1913 Picatinny rail coverage. The Santoprene material provide a rubbery surface for improved weapon control and rail protection. Easily cut for custom lengths" each panel fits one side of a carbine-length rail (18 slots). One panel per package. Manufactured by Falcon Industries" Inc.