This is the Apex3D B.O.S.S or “Bering Optics Scope Sentinel”
The Apex3DB.O.S.S plugs into your usb cover and provides protection for your USB port in conjunction with a magnetic usb cable. Simply replace the rubber cover on your scope with the B.O.S.S. TheB.O.S.S has a rubber base that helps guard against water getting into it. Simultaneously providing that extra bit of hold you need with higher caliber rounds and rifles with just a little more kick.