The NEC Short Zoom Replacement Lens is designed for use with select NEC PA-Series projectors. It provides 1.3x zoom with a throw ratio of 0.79 to 1.04:1 and is designed for 50 to 500" screens.0.79 - 1.04:1 Manual Zoom Lens (lens shift) for the NP-PA653U/PA803U/PA853W/PA903X projectors