IProtect O2 Beam Long Range 40/400 Lumens Aircraft Grade Aluminum Black CR1. Green light is best for low light conditions because the human eye recognizes the color green faster than other colors. Also perfect for hunting as some game cannot see green light. The mount with this light fits (20mm - 32.5mm) barrel and scope diameters and adjusts tighten and locks without tools. This light has an output up to 400 lumens. Specifications for IProtect 6689 O2 Beam Long Range 40/400 Lumens Aircraft Grade Aluminum Black CR1: Manufacturer: iPROTEC Color: Green Beam Color: Green Attachment Type: Riflescope Ring Battery Type: CR18650 Gun Model: Universal Weight: 1 lb Fabric/Material: Aluminum Light Output: 40 - 400 lumens IProtect 6689 O2 Beam Long Range 40/400 Lumens Aircraft Grade Aluminum Black CR1 What firearm models does the manufacturer say IProtect 6689 O2 Beam Long Range 40/400 Lumens Aircraft Grade Aluminum Black CR1 is compatible with? The manufacturer suggests that IProtect 6689 O2 Beam Long Range 40/400 Lumens Aircraft Grade Aluminum Black CR1 is compatible with Universal