The ERGO SuperLite Free Float Modular KeyMod Rail System provides a 1.8 outside diameter and a compact 1.35 inside diameter designed to create a clean and sleek profile. Ventilation cutouts aid in rapid cooling and provide substantial weight reduction. – 15 Version Weighs 10.6 ounces – The ERGO SuperLite Modular KeyMod Rail System KeyMod slots are located at the 3 6 and 9 o’clock positions allowing users to run with or without rail covers. The KeyMod rail provides multiple attachment locations for Ergo KeyMod accessories including Ergo WedgeLok; slot covers and as a host to all other KeyMod compatible products. – Manufactured entirely in the USA from 6061 T6 aluminum and Type III Class 2 hard anodized. The ERGO Superlite Modular KeyMod Rail System is available in two lengths model #4819-12 12 and model #4819-15 15. – Installation is simple using the standard ½ drive 1 3/16 crow foot wrench (not included) and all necessary mounting hardware is included. – Specifications: – 6061 T6 Construction – Type III Class 2 Hard-coat Anodized Finish – Lightweight one piece free float design – KeyMod design accepts Ergo and all other KeyMod compatible accessories – Full length seamless Mil-Spec 1913 Picatinny top rail – Scalloped Picatinny rail slots for comfort – Sleek 1.8 outside diameter and a 1.35 inside diameter – For AR-15/M16 platforms (Not AR-10 SR25 etc.) – Made to VLTOR Weapons Systems KeyMod Specifications – Made entirely in the USA.