High quality truss rod routing bits available with 3.5mm, 5.2mm and 6.2mm.HW Tungsten Carbide.3.5mm - For Carbon Rod Cavities5.2mm - For Single Action Truss Rod Cavities6.2mm - For Double Action Truss Rod CavitiesDimensions: Check photo gallery.Shanks:3.5mm bit: 6mm shank5.2mm bit: 8mm shank6.2mm bi..