They call them "Files for life" because the surface is infused into the glass not just sandblasted on top. This Spa Foot Bar is 6" long and made of tempered glass for strength and durability. Each bar has two different filing surfaces. One removes dry, callused skin, the other smooths, leaving feet with that "just from the spa" softness. You will love it for those dry cracked heels. Available in 7 colors.