Feeler gauge made of stainless steel with 32 different thickness blades. Foldable, easy and convenient to take and storeEasy identification: double markings with metric and imperial measurements, 0.0015 inch/0.04 mm to 0.035 inch/0.88 mm, sizes are etched into each blade for easy identification ENJOY: Foldable and flexible, this engine shim set will allow you to very quickly and accurately measure the spark plug gap and adjust the valve rocker arm clearance. you can easily take it with you and store it in your garage Anti-rust: gauge cover with anti-rust oil, does not rust and easy to open Usage: The shim set can be used for car/motorcycle mechanics but also for electronic products (3D printer) and musical instruments: guitar/acoustic/bass, perfect for measuring spark plug gap and adjusting rocker arm play. valve