The Rollerblade switch frame is taller than the standard aggressive frame. The frame was designed to allow more space for bigger wheels which result in faster and smoother ride. The frame was originally design for the Rollerblade point 8 skates or the new Rollerblade SOLO models. This frame can also be used on any other aggressive skates when the wheels are rockered down. The complete set of frames is sold with all the necessary hardware to fit your aggressive skates. Features: 4 72MM / 89A Rollerblade wheels. 8 Abec 5 bearings. 4 Rollerblade plastic antirocker wheels. Sizing: Small - fits boot size 6-10.5 Large - fits boots size 11-15