Simply snap over the top of the fence and lock to the wire mesh with steel hog-rings (included with each package) through the three pre-drilled holes on each piece. Manufactured using HDPE plastic with UV stabilizers, designed to endure high impact, resist the harmful effects of the sun and withstand severe weather conditions. Resists vandalism by using the hog-rings to permanently to attach the Safety Top Cap to the fence. Each bag comes with (5) 8' pieces, enough to do 40' of fence!