Two skates for the price of one! Quickly interchangeable frames allow you to switch from quad roller skates to inlines and back with ease. The boots feature adjustable sizing for growing feet, and expand up to 3 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. Roller Derby® is America's Skate Company since 1936.