Save 10% off the combined price when you buy the M4E1 Builder Set! This package deal includes the pieces you need to start building your own M4E1 (AR15) Rifle, including a M4E1 Threaded Upper Receiver, AR15 ATLAS S-ONE Handguard of choice and a M4E1 Stripped Lower Receiver.Includes: M4E1 Stripped Lower Receiver (Anodized Black or Magpul(TM) FDE Cerakote) M4E1 Threaded Upper Receiver (Anodized Black or Magpul(TM) FDE Cerakote) ATLAS S-ONE Handguard of choice All 3 pieces are finished in mil-spec Anodized Black or Magpul(TM) FDE CerakoteSpecifications: Shipping to FFL Dealer Required Yes Made In America? Yes Shipping to FFL SOT Dealer Required No Platform AR15 Weight(s) 7" KeyMod: 22.56 oz / 9" KeyMod: 23.14 oz / 12" KeyMod: 24.61 oz / 15" KeyMod: 25.49 oz | 7" M-LOK: 22.66 oz / 9" M-LOK: 23.27 oz / 12" M-LOK: 24.80 oz / 15" M-LOK: 25.75 oz