Chief's RPA Series Inverted Ceiling Mount is the top-selling projector mount in the industry! More RPA Series Mounts are installed in offices, schools and homes than any other mount. Why is the RPA so popular? Because it gives you everything you need for a quick installation, low-profile look and hassle-free projector maintenance. This product is designed for the following systems: Dell 2100MP; Dell 2200MP; Dell 3200MP; Dell 3300MP; Dell 4100MP; Hewlett-Packard sb21; Hewlett-Packard xb31; OPTOMA Cine Show H30; OPTOMA EP 731; OPTOMA EP 737.