Marshall "JCM800 Standard" Jack Rack. Hang your keys like a rock star with this replica Marshall Amplification Jack Rack. It is a wall-mounted amp head replica with four ¼" inputs where your included guitar jack keychains can hang. Easy to install. The Jack Rack is made from 1/8" thick injection molded plastic and decorated with a custom amp style decal. 8 x 3 x 1.5 in.