i fitted a little white catch thing to a secret flush door without a handle, you pushed it and it clicked and then the door opened a few inches so you could grab the edge. It had a magnet which attached to back of door face and the mech fixed onto the non rebated door frame. It was only small, the secret door is only 600mm X 425mm. I want to put one on a wall service hatch in a attic bedroom. I'm sure I bought it from screwfix but they only have the long bumper ones, do they work the same? How is the door held closed? What sort of hinges would I use if it needs to be pushed inward slightly to us latch the mech? Thanks