The product is a 5/32” (#21) pilot 1/4-28 threaded 100 degree countersink cutter aircraft tool. It is specifically designed for metalworking and aircraft tool applications. The countersink cutter creates a chamfer or bevel on the end of a hole to improve the appearance and functionality of the fastening surface. Its high-quality construction and precise design make it a reliable and essential tool for professionals in the CNC, metalworking, and aircraft industries.