The Bi-Fold Door Lock is designed to help prevent children from opening bi-fold doors, and to minimize the risk of pinched fingers. Simply place at the top hinge, no tools needed. Slide lock sideways for access. Clear plastic to blend in. Adjustable to fit most doors. Works on doors 1 3/8" thick and smaller. Comes with spacers/shims for narrower doors. Handle extension for ease of use.