Craftsman 2pc Dual Material Inch/metric Folding Hex Key Set The inch fold-up key includes 9 sizes: 5/64, 3/32, 7/64, 1/8, 9/64, 5/32, 3/16, 7/32 and 1/4 inch The metric fold-up key includes 8 sizes: 1.5, 2, 2.5, 3, 4, 5, 6 and 8mm.