Peerless PRGS Projector Mount, Black Two adjustment knobs to control tilt and roll image alignment and accurately hold image position, virtually eliminating any sag or drift Specifications: Pitch: +15 Degree /-20 Degree Roll: +/-5 Degree Swivel: 360 Degree (during installation) Pre-installed security screws provide tilt and roll locking ability to prevent tampering and adjustments Low profile design allows projector to be flush with the ceiling Quick release mechanism to easily service projector