The Tundra is Ultra-light weight/compact design, weighting 3.6 ounces. It is uses an Ultra-tough composite construction. Being innovative in pin design that improves sight picture and protects fibers. It has quick and easy fiber replacement and an aperture with a 1.8inch inner diameter. With a large circular field of view. Includes a level for balance and a reversible bracket for greater vertical adjustability. It also has a Glow-In-The-Dark shooter's ring. Designed to be adjustable for left and right handed users. Accepts any Apex Gear or TruGlo light (sold separately).