PureTrak PerfectGlide HD Mouse Skates for Logitech MX518/MX510 - Mouse Feet - 2 PACK 100% PTFE Material Provides the Absolute Fastest Glide Available Same as Original Fitment Thickness of 1.2mm (Thickest Replacement Skates on the Market!) Powerful 3M Backing Glue Life Expectancy of Twelve (12) Months or Greater