This is the same kit sold by many major AR-15 manufacturers. Made for us by a major weapons manufacturer in Texas that supplies other dealers and small/medium/high end manufacturers. This AR-15 Milspec Carbine Buffer Tube Kit includes - 6 position Carbine Milspec Buffer Tube - sourced from quality Alcoa aluminum extrusions. - Carbine Buffer Spring - Standard 3oz Carbine Buffer - Latch (end) plate and Castle Nut - MADE IN THE USA