Screw-Knob Quick-Release Clamp, 80mm jaws.
Screw-Knob Quick-Release Clamp. Traditional screw-knob clamps are tried & true and can deliver slightly greater clamping force than our Lever Release clamps. Clamps have 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 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
• B2-Pro fits Manfrotto 484RC2, 488, & 488RC2
• When clearance is an issue, choose our B2 LR II - the low-profile lever does not protrude above or below the clamp's profile.

Specs

1. Jaw Length: 3.2 inches / 80mm
2. Width (includes knob in closed position): 4.0 inches / 102mm
3. Height: 1.0 inches/ 25mm
4. Weight: 5.2 ounces / 147g
5. Price: $87

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