1. High Performance: Constructed with metal and grinding stone premium materials, ensuring stable performance, outstanding grinding performance, and durability for long lasting surface treatment results. 2. Enhanced Engine Performance: The uniform stone particles effectively remove metal protrusions inside the cylinder, leaving a smooth surface to improve engine performance and extend its lifespan. 3. Easy Installation: 4 inch in length and 10mm in width, these stones can easily be inserted into your cylinder honing tool, and can be conveniently removed for storage when not in use. 4. Powerful Function: Designed for honing engine cylinders, these replacement stones provide excellent precision and control, helping to achieve a smooth, finish. 5. User Friendly: These engine cylinder hone stones are easy to install and use, making them suitable for both professionals and DIY enthusiasts, saving you time and effort. Spec: Item Type: Engine Cylinder Stones Material: Metal + Grinding Stone Size: 4 inches Application: Can use with other engine cylinder hones stone mounts Package List: 3 x Cylinder Honing Stones 3 x Screws