Clamp Ulanzi Crab Clamp SB11533 with 1/4" and 3/8" Threads for Magic Arm/HD02/T099

The Ulanzi Crab Clamp SB11533 is a compact accessory clamp designed to attach cameras, mounts and small accessories to rods, bars and arms commonly used in photo and video setups. It provides standard external 1/4" and 3/8" threads for direct mounting of cameras, ball heads, cold shoes or adapters, and is compatible with products such as Magic Arm, HD02 and T099. The clamp body and tightening mechanism allow quick fixing and repositioning without tools, making it suitable for studio and field use where flexible mounting is required.

Advantages

The Crab Clamp delivers a simple and reliable connection between accessories and support systems, offering the convenience of both 1/4" and 3/8" external threads in one compact unit. Its clamping jaw adapts to round or flat surfaces, enabling fast attachment to tubes, rails or bars. The design supports repeated quick setups and adjustments while keeping mounted equipment stable during shooting.

Suitable for

• Mounting small cameras, action cameras or compact mirrorless bodies to arms and rails
• Attaching LED lights, microphones, monitors or accessories with 1/4" or 3/8" fittings
• Connecting ball heads, cold shoe adapters or extension threads to Magic Arm, HD02 and T099-style arms
• Temporary rigging on tripods, light stands, cage bars and slider rails

When it may not be suitable

This clamp is intended for small to medium accessories and is not designed as a primary support for heavy DSLRs with long telephoto lenses or large cinema cameras. It also may not be suitable for permanent outdoor installations in harsh weather unless additional protection or corrosion-resistant materials are provided.

Key specifications

• External thread options: 1/4" and 3/8" (standard external threads for mounting)
• Clamping range: fits common tube and bar diameters used in camera rigs and arms
• Material: durable metal alloy construction for stable hold
• Tightening mechanism: manual clamp screw for tool-free adjustment
• Compatibility: designed to work with articulating arms and fixtures such as Magic Arm, HD02 and T099-style mounts

How to use

Open the clamp jaw and position it around the target tube, rail or flat surface. Tighten the clamp screw until the clamp grips securely, then attach the accessory using the appropriate external thread (1/4" or 3/8"). Repositioning is done by loosening the screw slightly, adjusting angle or position, and retightening. Ensure threaded connections are correctly engaged and that the mounted accessory is balanced before releasing the support.

What to consider before purchase

• Weight and size of the accessories you plan to mount — ensure they are within practical range for a small clamp
• Diameter and shape of the tubes or rails you will clamp to — verify compatibility with the clamp jaw range
• Mounting thread required by your accessories (1/4" vs 3/8") and whether adapters are needed
• Environmental conditions — for prolonged outdoor use consider corrosion resistance and additional protection

Usage recommendations

For safe operation, use the clamp to support lightweight accessories and check all connections before each shoot. When mounting heavier items, pair the clamp with a secondary support or a more robust mounting solution. Periodically inspect the tightening mechanism and threads for wear and clean contact surfaces to maintain secure grip and longevity.