3 1/2" overall with split ring. Clear cylindrical housing with GLO-TOOB logo. LED lighting source is viewable from 360°. Medium impact resistant design. 3 modes: 100% constant on, 25% constant on and Flash. Waterproof: up to 200ft. Twist waterproof tailcap switch. Working temperature: 5°F to 131°F. Depending on mode selection, battery life could last from 4-15 hours. Includes black nylon detachable lanyard. Uses one AAA battery (included). Hang packaged.