The four-piece bolt is a type of expansion bolt. The function of the four-piece gecko is to firmly connect, lock, and fix various fixed objects on a vertical plane; the installation of the four-piece gecko requires pre-punching appropriate holes, and then put the expansion tube assembly of the four-piece gecko into the hole. Insert the bolts with washers on the four-piece lug into the fixing holes of the four-piece lug. Fix the object, align the four gecko expansion tube assemblies into the holes, tighten the four gecko bolts, and tighten. Anchor fixed objects to walls or foundations