Millet Buck Gold 4-16x 50 Side Focus Illuminated Multi Coat Rifle Scopebr Heavy Duty one piece main tube provides the foundation for precise lens alignment and other components br Shock-proof scopes need to absorb the heaviest recoil and field handling conditions without failure br The reinforced variable power zoom ring serves to seal and support the eyepiece securely br Our special sealing and purge methods for dry nitrogen fill include internal moisture removal paths in the eyepiece br Buck Gold scopes have a unique coil spring system which applies uniform pressure throughout the windage