B2-Pro/L: 80mm Screw-knob clamp

SKU: B2-Pro/L
$87.00

In Stock

Screw-knob Clamp, 80mm jaws

Why should you invest in a quick-release system? Because screwing your camera or lens onto a platform with standard 1/4"-20 screw is tedious and insecure. Not only is it a hassle to screw your gear onto that platform, but once installed the camera or lens is free to rotate; there's nothing to prevent it from coming loose. Why invest your money in a tripod and tripod head only to compromise your shots with an insecure connection between camera and head? Instead, adopt the Really Right Stuff quick-release system.

The Really Right Stuff quick-release system is based on the Arca-Swiss standard and has two parts: a quick-release clamp and a quick-release plate. You always need both pieces of the system. The clamp will stay on your tripod head/accessory all the time, and the plate will stay on your camera all the time. You will need to purchase a separate quick-release plate for each camera or collared, telephoto lens that you want to mount in the quick-release clamp on your tripod head.

Clamp jaws open and close in one of two ways: by twisting a knurled knob on our tried & true screw-knob clamps; or by flipping a single lever on our innovative, patented lever-release clamps. Traditional screw-knob clamps are tried & true and can deliver slightly greater clamping force than our Lever Release clamps.

The B2-Pro/L has dual mounts: center socket is countersunk on top but also threaded 3/8"-16. Mount by spinning onto an exposed threaded post or with flat head screw from above (accept M6 or 1/4"-20, not 3/8"). These clamps are appropriate for mounting on:
  • Any head or platform with exposed 3/8"-16 threaded post
  • Can drop onto a female socket tapped 1/4"-20 (for any RRS head) or metric 6 (for all others; all screws sold separately)
  • Any head or platform with exposed ¼"-20 threaded post - install a reducer bushing into the socket hole of the clamp
  • Any head or platform with 3/8"-16 female socket - purchase our stainless steel 3/8"-16 stud
  • Dual mounts: center socket is countersunk on top but also threaded 3/8"-16. Mount by spinning onto an exposed threaded post or with flat head screw from above (accept M6 or 1/4"-20, not 3/8").
  • When clearance is an issue, choose our B2 LR II - the low-profile lever does not protrude above or below the clamp's profile.
  • B2-Pro/L fits a verarity of heads which you can see HERE.
  • B2-Pro/L is 80mm (3.15") long, one central countersunk 3/8"-16 socket, two outboard 1/4"-20 sockets spaced 1.8"/45mm apart on center, captive knob, centering index marks, 5.1oz/144g


  • B2-Pro/L is appropriate for mounting on:
  • Any head with exposed 3/8"-16 threaded post
  • Can drop onto a female socket tapped 1/4"-20 (for any RRS head) or metric 6 (for all others)
  • Any head with exposed 1/4"-20 threaded post - install a reducer bushing into the socket hole of the clamp
  • Any head with 3/8"-16 female socket - purchase our stainless steel 3/8"-16 stud
    1. B2-Pro/L Clamp only, mounting hardware and tools not included
    2. user's guide
  • Jaw Length: 3.2" / 80mm
  • Width: 4.0" / 102mm
  • Height: 1.0" / 25mm
  • Weight: 5.2 oz / 147g
  • Center Hole threaded 3/8"-16
  • Outer holes threaded 1/4"-20 spaced 45mm apart on center