The Ergo Grip Modular M-LOK Rail System provides a 2eee outside diameter and a generous 1.8eee inside diameter designed to accommodate most suppressors while maintaining a clean and sleek profile. Ventilation cutouts aid in rapid cooling, and provide substantial weight reduction. The ERGO Modular M-LOK Rail System features integral anti-rotation tabs. M-LOK slots are located at the 3, 6, and 9 oeeeclock positions allowing users to run with or without rails. The rail provides multiple attachment locations for Ergo M-LOK accessories including Ergo WedgeLok slot covers and as a host to all other M-LOK compatible products. Manufactured entirely in the USA from 6061 T6 aluminum, and Type III Class 2 hard anodized. Installation is simple using the standard USGI barrel nut wrench (not included), and all necessary mounting hardware is included.