Top Plate (Alexa Mini) is just the top portion of Quick Cage (Alexa Mini). It attaches by four M4 screws on top and has the same M4 hole pattern found on the camera body which allows for attachment of ARRI brand handles and accessories. Arrays of 1/4-20 holes in standard spacing and multiple 3/8-16 holes for large accessories.

ARRI accessory mount also available in several places (3/8-16 screw hole with locating pins adjacent)..