Hex plug gauge 1.5MM,A/F - Hex. Plug Reversible double sided GO Gauge -1.507mm to 1.509mm A/F and GO Length 0.803mm to 0.805mm, Nogo Length 0.895mm to 0.900mm (Required Check The HEX Slot For 1.5 Cortex Screw HPG1507.1547.0800.0900)