The Supersonic Collection of products was developed with one thing in mind - pure race speed. When you're up against the clock or your fiercest rivals, know that you have the necessary products to break all barriers. Our ultra-minimalist SCOTT MTB RC SL Supersonic Edt. has an HMX carbon sole with a Corecell foam core for even more weight savings and ultimate power transfer. The dual-zone BOA® Li-2 Fit System secures the Carbitex carbon fiber uppers for a highly conforming fit.