The Charles Daly AR .410 Upper allows any AR-15 to be converted to a .410 shotgun. The CD .410 Upper features a 19in barrel"" chambered in 2.5in .410 bore. It has front and rear flip up sights"" picatinny quad rail forend and comes with a 5 round magazine. IMPORTANT: This upper works with mil-spec lower only. MUST USE CARBINE BUFFER TUBE. Upper includes buffer that must be used with carbine buffer spring for proper function. Failure to shoot without carbine buffer tube and provided buffer can cause damage to upper and lower. Overall cartridge length must be 2.29inches or less for proper function.