Wedges today, especially plastic ones, have a tendency to slide out during use. The Lock Technology LT276 Self Locking Door Wedge has a wash board/wave ripple surface to it. This allows easy entry between the door and rubber strip. The rippled wave-like surface securely locks the wedge in place making it almost impossible to slide out. This tool makes a great addition to a technician's lock out tool kits, and is also a great aid when completing window regulator replacement to hold glass securely in position during use.