![GBD Flex-Hone](http://pmdproducts.com/cdn/shop/products/GBD_BOX_Flexhone_a60e1cb0-55fd-42b5-98db-8cdd82498f42_600x.jpg?v=1670020682)
4 1/4" commercial grade Flex-Hones Aluminum Oxide. Nikasil Applications Hones are made with a softer material, Aluminum Oxide. These special hones are required for today's coated aluminum cylinders. These aluminum oxide hones are recommended for nikasil and chrome coated cylinder bores.