The 416 Plain Plates are 46mm tall, 51mm wide and 0.90mm thick. Made in UK from steel, brass plated. Work best on mouldings with backs 18mm or more wide.
Two small screws fix the plate to the back of the frame moulding. A third longer screw goes into the wall. All three holes are 4.4mm dia and raised to take countersunk head screws. Plates are typically used in pairs, one either side.
Sometimes also known also as Picture plates, Keyhole hanging plates, Picture hanging plates, Keyhole mirror plates and Keyhole picture plates.