1. Purpose: To prevent the valve from jumping during engine vibrations, which could damage its seal. Due to the elasticity and tension of the valve spring, direct disassembly by hand or with unsuitable tools may pose safety risks. This tool ensures safe operation, prevents spring damage, and extends its service life. 2. Easy to Use: Pull the jaws together to the smallest position, insert them under the valve spring seat, and then turn the handle. Press the left palm firmly forward to ensure the jaws fit tightly against the spring seat. After installing or removing the valve lock plate, turn the handle in the opposite direction to compress or release the valve spring, then remove the tool. 3. Complete Accessory Range: The valve spring tensioner includes a Cclamp (max. jaw opening: 300 mm), 5 collets (diameters: 16 mm, 19 mm, 23 mm, 25 mm, 30 mm), 3 pressure screws (lengths: 70 mm, 120 mm, and 120 mm), and a 100 mm hand lever—covering all common needs. 4. Wide Range of Applications: This valve spring compressor tool is suitable for assembling and disassembling overhead valves on motorcycles, beach bikes, cars, and other small engines.