Features: The diameter of trimmer head is 8 inches, the diameter of central hole is about 25.4mm/1 inch. Suitable for most of trimmer. This trimmer head is made of high quality steel wire, strong and durable, and the steel wire is not easy to fall off. When hit by stones and lumps, it still works. Easy to install, simply screw the trimmer head onto the trimmer unit for quick set up. Two packs different adapters kit for different needs. Can efficiently remove all the moss and messy weed in your lawn, garden, walkways. Applicable to brick road, paving stone, pavement joints.