The HE403B-GR is designed for day and night use. It's durable and reliable construction is unaffected by extreme weather conditions. The HE403B is parallax-free with unlimited eye relief and field of view. Its green LED technology allows up to 50,000 hours of operation on one CR2032 battery and has up to 4x more efficiency when used on high brightness settings. The optic features shake awake technology that powers the optic on with slight movement of the unit. It may be installed on various firearms such as shotguns, pistols, air rifles and crossbows. The HE403B-GR is compatible with standard mounts, a low mount and 1/3 Co-witness mount is included.