A Manfrotto 030-14 quick release plate for heads and accessories. Standard 1/4-20 thread for camera mounting. Choose style in the drop-down below.
Flat bottom plates have a slotted mounting screw that requires a tool like a coin or screwdriver to fix to your camera, but the camera can then sit flat on its base with the plate on.
Thumbscrew plates have a larger, grippable camera mounting screw that can be loosened and tightened by hand, but the protruding thumbscrew means that the camera can't sit flat with the plate attached.