This feeler gauge measures 0.0015-0.035" (0.04-0.88mm) for versatile and accurate usage. It's a precise 32 blade thickness gauge for imperial/metric width and thickness measurement. Our 32-blade feeler gauge is an ideal spark plug gap tool that reliably measures gaps, clearances, and tight tolerances, ensuring precise tuning of your spark plugs and other components where precision is necessary. Coated in an anti-rust oil, the feeler gauges metric / imperial are incredibly resistant to corrosion and ensure a smooth and easy opening action. Perfect for everyday use in a wide variety of applications.