M4 = 7mm spanner / overall diameter 10mm / overall height 4.5mm
M5 = 8mm spanner / overall diameter 11.8mm / overall height 5mm
M6 = 10mm spanner / overall diameter 14.2mm / overall height 6mm
M8 = 13mm spanner / overall diameter 18mm / overall height 8mm
M10 = 15mm spanner / overall diameter 21.8mm / overall height 10mm
M12 = 18mm spanner / overall diameter 26mm / overall height 12mm