The Slip-Grip (one way slide tube) is designed to slip easily in the direction of the arrow, but lock in place in the opposite direction. This allows a person to be moved up the chair or bed without fear of them slipping back down, in fact the super grip material used on the outer side of the Slip-Grip will in itself prevent someone from slipping forward again easily, therefore alleviating the need in many cases for a lap strap.