The product supports all ISO518 hot shoe flashguns with a locking pinhole.
It's made of plastic, but it has a 1/4'' thread at the bottom side to support lots of studio devices with standard 1/4'' thread.
It's compatible with studio light stand which has a 1/4'' thread like iShoot IS-200 light stand.
It's compatible with most Nikon, Canon, Nissin, Sunpak, Sigma, Olympus, Metz, Vivitar flashguns.
It doesn't support Sony & Konica & Minolta flashguns.
Approximate size is 74x68x10mm.