The Kirk BL-A7R4 L-Bracket with built-in industry-standard Quick Disconnect Socket custom-designed for the Sony A7R MK IV. It weighs only 2.9 ounces & has a captive 1/4-20 stainless steel mounting screw. It has been crafted from 6061-T6 Aluminium with a black anodized finish. For ease of use, it comes with sensor centring lines & a hand strap loop. It also features a slotted design for additional side port access in addition to a built-in hex wrench system.