Metric: Conform to BS 192 : 1982 & DIN 3110.BA: Conform to BS 1842 : 1952.Set6 Piece BA: 0 x 2, 1 x 3, 4 x 6, 5 x 7, 8 x 10, 9 x 11BA.6 Piece Metric: 3.2 x 4, 4 x 5, 5 x 5.5, 5.5 x 6, 6 x 7, 7 x 8mm