Product Descriptions 1. High Quality Material: Made from quality steel with black coating, corrosion resistance, great strength, not easy deformation, durable and light weight 2. Functions: Can conveniently, quickly and accurately measure valve spring installed height. Suitable for most V8 engines 3. Easy & Convenient to Use: Install our 4929 Height Micrometer just like a valve spring, then expand the tool until it has seated the valve, locks and retainer 4. Precise Reading: Simulated installation allows ultra precise readings. This tool is read like a micrometer, accurate to .001". Its measuring height range is 1.600 inch-2.200 inch .