“What” a French Cleat .. Could be a Freedom Cleat … This is a highly effective, adaptable and customizable mounting systems. At its heart a board with a 45 degree bevel is mounted to a Wall / Supporting surface and a board with an opposing 45 bevel is mounted to the object to be hung. Jump on Youtube and search; French cleat, a few good videos that show this system in use.. or Google it. I mounted 2 parallel cleats to my shop wall .. 3/4” thick x 3 1/2” x 10 feet, 3 1/2” Deck screws mounted into the studs. Custom mounts for: Toys – Lumber – Tools and Whatnots .. Easy to: Rearrange – Customize etc .. I like this system.