Two Vets Tripods Inc 55mm Dual Tension Ballhead W/ Area 419 Arcalock QD Black 4in. This innovative clamping system when used alongside the Area 419 Arcalock rail effectively eliminates the unwanted forward movement that often occurs when a rifle is clamped into standard clamps. What's even better is that this clamp is fully compatible with any Arca-style rail on the market as well as pitanny rails making it a perfect upgrade for any setup. Additionally the 55mm Dual Tension Ballhead has become increasingly popular since its launch. Featuring dual tension adjustments it includes a large knob for coarse adjustment and a smaller knob for fine-tuning allowing you to precisely dial in the perfect balance for your shooting style and needs. This flexibility has made it a favorite among shooters who demand accuracy and control. Specifications for Two Vets Tripods Inc 55mm Dual Tension Ballhead: Manufacturer: Two Vets Tripods Inc Color: Black Attachment Type: Picatinny Weight Capacity: 20 lb Height: 3.25 in Package Contents: Two Vets Tripods Inc 55mm Dual Tension Ballhead Two Vets Tripods Inc 55MM419QD: 55mm Dual Tension Ballhead W/ Area 419 Arcalock QD Black 4in