Key benefits - Cam action design provides secure locking of the valve spring in the tool, enabling safe and controlled compression. - Facilitates removal and installation of valve springs and spring retainers with the cylinder head in place, simplifying maintenance jobs. - Designed for overhead valve engines, compatible with OHV, OHC, and CHV cylinder heads. - Professional overhead valve spring compressor that is easy to use, offering reliable, straightforward operation. What it does - Compresses valve springs for safe removal or installation. - Exposes and allows removal of spring retainers, then decompresses to release the spring. - Supports replacement of valve springs and valve stem seals as part of engine service. Use scenarios 1) Valve spring and valve stem seal replacement on engines with the cylinder head in place, including OHV, OHC, and CHV designs. 2) Removing valve springs and spring holders during engine overhaul or inspection on overhead valve engines. 3) Installing new valve springs and reassembling spring retainers on OHV/OHC/CHV engines as part of routine maintenance or repair.