Really Right Stuff B43AF
Plate for Mamiya 645AF , 645AFD (I, II and III), ZD and P645
$50 Shipped and Paypal'd in the US

Like new condition and used sparingly during the past 3-4 months. This clamp is specifically for 645AF family and has two nubs which interlock with the base of the camera, thus ensure the plate will not spin - period. For more info, here is RRS' webpage. And a picture of the actual plate for sale here -