The NP17ZL 1.25 - 1.79:1 Short Throw Zoom Lens w/Lens Memory from NEC is one of six optional lenses available (in addition to the standard lens) for the NEC NP-PX700W/PX750U/PX800X and NP-PX700W2/PX750U2/PX800X2 projectors. It is designed to support a variety of specific installation environments, such as conference rooms, halls, and exhibitions. The lens is easily installed by end users and doesn't require any special tools.