This is a Seekins Precision Stripped Lower Receiver known as the SP223 Gen2 chambered in 223 Remington, model 0011000008.
Precision CNC machined from solid billet aluminum" the SP223 Billet Lower is the best AR lower receiver available. Far exceeding Mil-Spec requirements" the SP 223 has features not found on standard lowers such as the Seekins Precision Enhanced Bolt Catch" receiver tensioning screw" ambi-bolt stop assembly and an oversized trigger guard. These features combined with superior fit and finish make the SP223 the perfect foundation for any AR build.
Features:
Ambidextrous Bolt Release
SP Enhanced Bolt Catch
Upper Tensioning Set Screw