The HE403B-GR is an Elite version of our HS403B small compact micro red dot optic. Employing Holosun's new Green LED technology, the lifetime for one CR2032 battery can be up to 5 years and has up to 4x more efficiency when used the high brightness settings! This optic features our 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.