The DI Optical FC-1 prism sight offers virtually parallax free sighting in a light weight package. Weighing just 6 oz with battery and mount it is still an extremely durable optic. Made from 6061-T6 aircraft grade aluminum it is submersible down to 10 feet. It has 40 clicks of adjustment, a single push button illumination control with both day and night vision settings and a built in shut off after 10 hours of no movement.