High performance PhotoChromatic shell is 80 percent tougher and changes color even faster. Features interchangeable fluorescent sight rings, BombProof 1-piece machined micro groove pins, machined aluminum guard for maximum durability and pin protection. Calibrated horizontal and vertical gang adjustment. Sculpted base with oversized clamping dovetail. PhotoChromatic shell. Interchangeable fluorscent sight rings. Machined aluminum guard.