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Really Right Stuff B2-mAS Screw-Knob Clamp with 1/4″-20 Screw

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Really Right Stuff B2-mAS Screw-Knob Clamp with 1/4″-20 Screw - Main image
$12.97 $19.95 In stock

Category: General Photo Accessories

The Really Right Stuff (RRS) B2-mAS is a compact, ultra-durable Arca-Swiss compatible quick-release clamp designed for precise camera and accessory mounting. CNC-machined from aircraft-grade aluminum with stainless steel hardware, it provides exceptional clamping power and rigidity in a lightweight form factor. The manual screw-knob mechanism allows for fine control when securing Arca-style plates, with laser-engraved index marks to assist with nodal point alignment and panoramic setups. Featuring a central counter-bored hole and an included 1/4″-20 flathead screw, the clamp attaches securely to ball heads, monopods, bracket arms, or custom mounting rigs.

Key Features and Specifications

* Arca-Swiss Compatibility: Accommodates standard Arca-style dovetail quick-release plates and rails from Really Right Stuff, Wimberley, Kirk, and others.
* Precision Screw-Knob Operation: Texturized aluminum screw-knob provides positive, secure locking force and smooth jaw adjustment.
* Laser-Engraved Alignment Scale: High-contrast millimeter index markings along the jaw aid in precise centering and repeatable placement.
* Aircraft-Grade Aluminum Construction: Machined from solid bar-stock aluminum with a hard-anodized black finish for high wear and corrosion resistance.
* 1/4″-20 Threaded Mounting: Features a counter-bored center mounting hole and includes a 1/4″-20 stainless steel screw for direct attachment to support gear.
* Compact & Lightweight: Designed with rounded corners to minimize snagging and reduce overall gear weight.

Condition and Included Accessories

* Included Accessories: Really Right Stuff B2-mAS Screw-Knob Clamp and 1/4″-20 mounting screw included.

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Standard Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

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Express Shipping · United States: $3.99

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United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

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Customer Reviews (4.8 / 5 · 5 reviews)

Leo K. ★★★★★

The machining on this clamp is incredibly precise—my plates slide in smoothly with zero wobble. It’s compact enough for my travel tripod but still feels solid enough for my heaviest lens setup.

Michael N. ★★★★★

Finally found a clamp that doesn't slip even with my heavy telephoto lens. The 1/4"-20 screw fits perfectly and the whole thing feels rock solid on my tripod.

Emma Q. ★★★★★

The screw-knob tension adjustment feels precise and locks down tight without any play, which is exactly what I needed for my telephoto setup. It's noticeably lighter than my old clamp but still feels rock solid on the tripod.