Chess Tools Guitar/Bass Multi Tool 17 piece Universal Bass & Guitar Tool with the most frequently required allen wrenches in mm and inch; 6x Ballhead allen wrench 5mm, 4mm, 3mm, 2,5mm, 2mm, 1,5mm, 7x Ballhead allen wrench 1/20", 1/16", 5/64", 3/32", 7/64", 1/8", 3/16"; 1x Flat 2,5mm 1x PH1 (Phillips) Screwdriver, 1x Socket for Truss Rod 5/16" and 1x 1/14", Sockets exchangeable, Material highquality CV-Steel