Head Set Product Type Head Set Compatible Thread Size 1/4 In.-20 Compatible Rivet Nut Body Type Hex Material Steel Overall Length 2 1/2 in System of Measurement Inch Compatible Insert Type Rivet Nuts Compatible with Manufacturer Model Number FL5-HS-00748 FL5-HS-00848 FL5-HS-09148 M-2520-250 Includes Headset Only