Aero Precision M5 ATLAS R-ONE M-LOK Handguard. Machined from 6061-T6 Aluminum with an anodized black finish. The ATLAS R-ONE attachment system provides a slim yet strong mounting platform with even clamping pressure. Features a full top rail for optional attachments, quick disconnect sling sockets at the 3, 6, and 9 o'clock positions, and compatibility with low profile gas blocks as well as AR308 upper receivers and barrels. Not compatible with M5E1 Enhanced Upper Receivers.