Measures 8 7/16" wide by 12 7/8" long by 1 1/8" thick. It attaches with a screw-type thumbscrew and has 2 pins. Sometimes you need to do an adjustment to match the pins up with any particuliar camera. There is usually a flat plate that holds down the spring stop on the base, but this one doesn't have one, would be an easy addition. Overall decent user condition. $125 plus postage. Paypal accepted.