Total number of hours various for each unit. The most hours are 7000 on 1 an almost 5000 on the others.     Optoma ZX310ST DLP XGA Short Throw Laser Projector offers a high-quality viewing experience with 3000 ANSI Lumens of brightness and a contrast ratio of 15000:1. This projector features a fixed lens, native 4:3 aspect ratio with compatibility for 16:9, and a maximum resolution of UXGA (1600 x 1200 @ 60Hz). It is equipped with various connectivity options such as HDMI, USB, and VGA, and comes with built-in speakers and a 3D video capability. The projector is designed for ceiling projection and is compatible with a range of operating systems including Windows, Mac, Linux, and Android.