The Novoflex Q=Plate series QPL-1 square quick release plate fits any Arca-type quick release system (except the Arca Swiss Flip-Lock). It features a 1/4"-20 camera screw, on a 1.65" square plate that can slip in from any direction.
The bottom edges are dovetailed for smoother loading and unloading from the clamp, as well as less abrasions. The screws of the Novoflex plates work with both traditional flathead screwdrivers as well as 5/32" Allen wrenches.
Note: The Novoflex Arca-type quick release plates are thinner by the slimmest of margins than Arca-Swiss quick release plates. They are not recommended for use in the Arca-Swiss Flip-Lock quick release clamp.