2 Skates in one! Quickly interchangeable frames allow you to switch from quad roller skates to inline and back with ease. The black/blue boots feature adjustable sizing for growing feet, and expand up to 4 sizes with the push of a button. With these versatile skates, you can enjoy all that skating has to offer. Switch out the frames by using 2 allen wrenches. Fits true to children's U.S. shoe sizes. Medium adjusts from size 3 to 6. Small fits 12 to 2.