Had to pull a Pioneer Plasma of the wall a few years ago for service. It was a Peerless mount that used a five sided security screw. Looked like a allen head screw but had five sides instead the normal six that an allen head has, Peerless calls it a Penta Pin Tool. Managed to get it off without the tool but ordered it along with new screws, I think the four tools and two new screws were like ten bucks plus shipping.