I'm buying some really right stuff tvc-33 legs, and arca Swiss z1 ball head and a rrs b2 as2 clamp. I just need the qr plates. It will be for use with a 500 f4 and I see there are two things listed on rrs website....a foot and a multi purpose rail. Do I need both of these things? Does the rail connect to the foot then clamp in? It's referred to as a replacement foot but it just mounts to the stock foot or what?
Pictures would help if anyone has them.
Thanks!!!

