Features: The astronomical telescope accessory set includes small dovetail plate and base, with screw. It can help astronomy enthusiasts to observe and locate more conveniently and quickly. Provide precise positioning function, allowing users to easily find and enhances the observation experience. Exquisited designing with high sensitivity, which help to quickly focusing and locate. The base is stable, easy to install, and provides stable support. Specifications: Material: Metal Color: black Size: about 42x32mm/1.65x1.26inch(more detail size please refer to pictures) Base width: 42mm Base length: 29.5mm Inner trapezoidal bottom width (bottom): 33.4mm Inner trapezoidal bottom width (top): 28.7mm The basic height of the internal part is approximately. 9 millimeters Distance between two holes (center distance): 12mm Hole inner diameter: 4.4mm Curving diameter: 100mm Swallowtail board length: 42mm Swallowtail board width (bottom): 32mm Swallowtail board width (top): 20mm Swallowtail board height: 11mm Note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution. Package includes: 1pc Dovetail Board 1pc Bracket Base 1pc Screw