Build a Lead Star LSA-15/AR-15 into any configuration with the Lead Star Builder's Kits! With this kit, you now have the freedom to choose your own trusted parts to build the rifle of your dreams Upper Receiver Precision CNC machined from 7075-T6 billet aluminum. Lead Star's truss system design reinforces key areas for increased strength without added weight. Flat top Picatinny design for versatility in mounting optics and other enhanced components. CNC engraved numbered rail system for indexing. M4 feed ramps for added reliability. Type III Class 2 hard coat anodized. Designed to be compatible with MIL-spec lower receivers so it can be used if necessary but lines will not match. Weight: 7.9 oz   Lower Receiver Fully CNC machined from 7075-T6 billet aluminum for extreme precision and enhanced durability. Lead Star's truss system design reinforces key areas for increased strength without added weight. Front magwell grip surface designed for the operator to grip and maintain weapon control even in the most extreme conditions. Beveled magwell entry allows faster magazine changes. Tension device to increase rigidity between upper and lower receivers. Built-in trigger guard eliminates the need for a flip down trigger guard. Type III Class 2 hard coat anodized. Designed to be compatible with MIL-spec upper receivers so it can be used if necessary but lines will not match. Weight: 10.2 oz   15" Ravage Handguard CNC machined from 6061-T6 aluminum for extreme precision and enhanced durability. The unique design offers ultra capture around the barrel nut eliminating the requirement for anti-rotation tabs. Eliminates harmonics from attached accessories greatly improving weapon accuracy. Four Picatinny slots at the 12 o'clock position for mounting back up sights. M-LOK slots at the 3 and 9 o'clock positions and full-length M-LOK at the 6 o'clock position for mounting only the Picatinny rail needed or accessories. Includes barrel nut, shims, and mounting screws. Compatible with 14.5" barrels. 15" measurement is taken from the bottom of the handguard. The mouth of the handguard is designed so muzzle device stays tucked in handguard for a clean appearance. Type III Class 2 hard coat anodized. Weight: 7.9 oz Barrel nut, shims, and mounting hardware: 1.6 oz. Barrel nut installs with standard A2 barrel nut wrench.