Ratchet Lock Knob: The connecting part of the nut clamp is a ratchet type that can be pulled and rotated. When you look at other accessories and cant turn, you can pull the knob to adjust the screw. 【1/4 and 3/8 Mounting Holes】 Comes with mounting holes for 1/4"-2 and 3/8"-16. Allows you to mount a variety of accessories to suit your shooting needs. Convenient to Use: The NATO clamp can be firmly fixed to each part because it is a single piece mold. Attach to the nut rail and attach accessories such as magic arms and cold shoes with a 1/4" screw hole. Made of durable aluminum: The aluminum alloy is used with highly corrosion resistant material, so it wont rust even after long periods of use. It weighs only 2.5 oz (70 g), making it a convenient item for photographing. The precision finish makes it easy to use in every detail while also making it very useful for mounting equipment. Product Specifications: Dimensions: 1.1 x 0.7 x 0.8 inches (28 x 19 x 20 mm); Net Weight: 0.8 oz (23 g); Package Size: 4.7 x 3.9 x 0.6 inches (120 x 100 x 16 mm); Package Weight: 0.8 oz (23 g); Material: Aluminum alloy; Note: Please check the size Package Contents: NATO Clamp: 1 pc. (Safe Quality) We ship it from Amazon delivery center, so you can quickly and safely deliver it to your home. There may be scratches or dents on the outer box during transportation, but please rest assured that the contents will not affect the product. Also, if you have any questions or problems about the product, please feel free to contact us at any time.