AOP plastic socket holder is a standard necessary parts to help your sockets/inserts to fixed wood formwork in precast concrete. There have two or three nail hole to use nail fixed to wood formwork. There also are plastic screw bar to fix the socket thread. You can fix the nail plate to wood formwork at first and then thread the screw bar into sockets or inserts thread. After then to removable the nail plate. The plastic socket holder can reuse many times.