The Leupold's VX-3L Mounts like a 40mm and delivers 96% more total light throughout. The cresent removed from the lower radius of the objective lens forms the Light Optimization Profile for the scope to be mounted so low. Incredible low-light performance combined with balance, accuracy, and a tight check weld give the VX-3L everything it needs.Field of view in feet @ 100 yards: 29.8' Low/11.0 High, Weight: 16.3oz., Eye Relief: 4.5".