Size:L Outer material:Acrylonitrile Butadiene Styrene (ABS) Included components:Guide Batteries included?:No Department:Boys' Product Dimensions:21 x 15 x 4 cm; 141 Grams Features: Used for Fast helmets or other modified helmet equipment guide rail. Including screws and nuts, it is easy to install onto helmet. With it ,you can attach lights, lasers, cameras or other devices to helmet by using standard arc rail dovetail adapter(not included). It can be firmly fixed on your helmet, not easy to drop. Nice accessory for your combat helmet, providing much convenience. Specification: Condition: 100% Brand New Material: ABS Color: Black, Green, Mud Color(Optional) Single Rail Size(L * W): Approx. 19 * 6.3cm / 7.5 * 2.5in Weight: Approx. 129 - 142g Packing List: 1 x Pair of Rails 4 x Screws 4 x Nuts About this item PACKING LIST -- Including screws and nuts, it is easy to install onto helmet. FIT FAST HELMETS -- Used for Fast helmets or other modified helmet equipment guide rail. EASY TO INSTALL -- It can be firmly fixed on your helmet, not easy to drop. MULTIFUNCTIONAL -- With it ,you can attach lights, cameras or other devices to helmet by using standard arc rail dovetail adapter(not included). MORE CONVENIENT -- Nice accessory for your combat helmet, providing much convenience. PACKING LIST -- Including screws and nuts, it is easy to install onto helmet. FIT FAST HELMETS -- Used for Fast helmets or other modified helmet equipment guide rail. EASY TO INSTALL -- It can be firmly fixed on your helmet, not easy to drop. MULTIFUNCTIONAL -- With it ,you can attach lights, cameras or other devices to helmet by using standard arc rail dovetail adapter(not included). MORE CONVENIENT -- Nice accessory for your combat helmet, providing much convenience.