Features: brand new and high quality Built-in 2 spirit bubble level, which ensure the photography precisely in horizontal orientation. 38mm Arca-Swiss standard U-shaped grooves of the clamp, which can protect your camera from accident drops. Made of lightweight aircraft-grade aluminium material, CNC processing, hard-anodized anti-oxidation surface treatment. Self-euipped with a knob, made of all metal, more durable and non-ageing. Standard 1/4" & 3/8" thread screw hole, for any arca style plate, camera bars and multi-purpose rails. such as RRS, Arca-Swiss, KIRK, Wimberley, Markins, Sunwayfoto, Kangrinpoche, Benro etc. Specifications: Material: Aluminum Alloy Model: QR-110N/QR-50N/QR-70N/QR-90N(Optional) Card Slot: 38 mm/1.49 inch QR-50N Screw Hole: UNC 3/8 QR-110N/QR-70N/QR-90N Screw Hole: UNC 1/4 & 3/8 Spirit Bubble Level: 2 Package Includes: 1 Piece Quick Release Clamp note: Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!