Completely invisible fittings with fool proof security. Security Anti-Theft Picture Hanger T-Screw Kit. A T-Screw Kit for any type of Wood orPolymer Frames. T-Screw is turned with T-screw spanner which slips behind the frame. When turned it locks into the slotted plate on a wooden frame. It can then only be released with a similar spanner. This hidden fixing makes the frame safe and secure on the wall. No ugly picture or mirror plates sticking out from either side.