30mm one-piece tube made of 6061-T6 aircraft grade aluminum.�st (front) focal plane reticle.�ll lenses are fully multi-coated, providing over 95% light transmission. Type H lens coating is standard, and H2 coating is available as an option. �oil spring provides the shooting accuracy, and keeps a point of impact securely against the heavy recoil.�indage/Elevation adjustment turrets are of a low profile, and waterproof without a dial cap.