Replaces nylon straps, wood clamps and other unconventional methods to secure slabs to an existing A-Frame. The arm and pad are lowered against the slab and the slider mechanism locks the arm into place. A tamper resistant key prevents unauthorized access. The base is inserted into the base of an existing A-Frame, and safety chains secure it to the A-Frame. The 3mm thick walled tubular steel upright is inserted into the base and locked in place with a hardened steel pin.