Supplied with 1/4-inch-20 camera screw.
Comments about Bogen Quick Connect Plate 3157N Rectangular:
This is a fine product.
The photo shows the 3157N attached to the quick release locking mechanism. The lock is NOT INCLUDED. This is only the small rectangular plate with screw.
As for the product itself, my one complaint is that the metal tab used to turn the screw, though very durable, is too stiff to be picked up with a fingernail. Once the plate is screwed in place, if I want to remove it, I often have to find a screwdriver or knife to pry it loose.