Aero Precision Atlas R-One, M-LOK, Handguard, 15, Anodized Finish, Olive Drab Green, Fits AR15 Rifles APRA501178A The ATLAS R-ONE is the latest addition to the Aero Precision Handguard lineup. Machined from 6061-T6 Aluminum" the R-ONE line of handguards are designed with size and weight in mind" providing the perfect handguard for your lightweight build. Their proprietary ATLAS attachment system is a durable and dependable mounting platform" maintaining a slim profile while still providing the strength and stability customers have grown to love from Aero Precision handguards.