A square format body plate for affixing to most Pro size SLR cameras, or cameras with an accessory battery pack.
The curve on the back of the camera is 1/2", roughly the same as Canadian or US dime.
Nikon D1, D2H, D2X, D3, D3x series
Battery packs: MB-D10/D80/D200/D100, MB-40
EOS 1D/1Ds series
Battery Pack Fit: BG-E1/E3/E4/E5, etc.
5/32 Allen Key
1/4" LARGE head mounting screw
Hard anodized brushed finish
1/4" threaded accessory hole