Feeler gauge made of stainless steel with 32 different thickness blades. Foldable, easy and convenient to take and store Easy identification: double marking with metric and imperial measurements, 0.0015 inch/0.04 mm to 0.035 inch/0.88 mm, sizes are engraved in each blade for easy identification PLEASURE: 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, never rust and easy to open Use: The game of wedges can be used for auto/motorcycle mechanics but also for electronic products (3D printer) and musical instruments: guitar/acoustic/bass, perfect for measuring spark plug gap and adjusting valve rocker arm play< /p>