SPT5 Draper Tools Spark Plug Tools Draper 10 Blade Feeler Gauge Metric 100mm long taper blades. Each blade is marked with its size and folds into a plated steel case with thumbscrew. Blade sizes: Metric: 0.05, 0.10, 0.15, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, and 0.80mm