[Make sure you buy the right ones: G502 wireless has different skates than the wired G502]My 2 center skates were both peeling at the edges, and getting caught in my mousepad. From what I read, the material that these replacement skates use is the same that ships with the mouse, which is good.The package includes:2 sets of every skate on a piece of 3M papera small microfiber cloth2 alcohol wipes (to clean residue after removing old skates)plastic tweezers (I used them to peel up the old skates)Installation is easy. After peeling off the old skates (make sure you get rid of every layer) it should just be the plastic housing of the mouse left. I used the alcohol wipe to clean the area. Then I removed the replacement skates off the 3M paper and placed them in their spots. Pushed them real hard for a good 30 seconds. There's a thin white-ish film covering the tops of the skates (opposite side of the 3M paper) to be peeled off after installation.Feeling good as new!