Features: Design: Allowing to convert 11mm to 20mm rail. Multifunctional: 20mm top rail allow installation of sights, torches, lasers Material: Constructed of premium aluminum alloy material, strong and sturdy. Easy Installation: Easy to install and quick to detach. Wide Application: Perfect for huntings, war game, militarys. Notice: 1.Actual color may be slightly different from the image due to different light effect 2.Please allow 1-3cm deviation due to manual measurement Description: Material: Aluminum Alloy Color: Black Total Length: Approx. 100mm/3.93inch Bottom Rail Length: Approx. 75mm/2.95inch Top Picatinny Rail Width : Approx. 20mm/0.78inch Bottom Dovetail Rail Width : Approx. 11mm/0.43inch Weight: Approx. 72g Package List: 1 x Rail Mount, 2 x Hex Wrench Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.