The FDERADIAN AR-15 15.5" M-LOK Upper Receiver and Handguard features premium billet aluminum construction with a sleek black finish for enhanced durability and performance.AR-15 15.5" M-LOK Upper Receiver and Handguard Model 1Billet aluminum construction for superior strengthM-LOK compatible rail system for versatile accessory mountingBlack anodized finish for corrosion resistanceDimensions: 4.75" x 5.40" x 33.45"SKU: R0620This precision-engineered upper receiver and handguard combination provides a solid foundation for custom AR-15 builds offering reliable performance and extensive modularity through the M-LOK attachment system.