The Mini Quick Release Adapter Receiver is reinforced with helicoils and so the screws can only be screwed from the outside.  The upper section has 1/4"& 3/8" thread holes; the 3/8" thread hole comes with ARRI Anti Twist holes to prevent turning loose.  The lower section has a 3/8" thread hole. It also fits with the ARRI Anti Twist Adapter Plate, the ARRI Anti Twist Plate 90° Version, the SmallHD Anti Twist Adapter Plate & SmallHD Anti Twist Plate 90° Version (which are sold separately).

The Lever is black and easy to change; coloured levers sold separately.