The stylization of the YHM Second Billet Upper Receiver is reminiscent of the YHM SLR handguards. Because YHM was working with Billet 7075-T6 Aluminum it gave them the ability to really create an eye catching upper receiver. This upper is made from 7075-T6 aluminum (Billet). It has M4 Style feed ramps and the inside is coated with dry film lube. It accepts Standard upper receiver parts (dust covers, forward assists, etc.) and Mil-Spec Lower receivers. It will fit and function with your standard lower receiver. It has a Hardcoat Anodized matte black finish.