Designed for use with R21 (WC and Racing) and the new R22 WC race plates, the SPX 15 ROCKERFLEX is an elite-level, competition race binding. The strongest coupling strength and longest elastic travel on the market deliver instant power transmission, precision, and control with superior shock absorption for reduced pre-release. The short mounting zone and semi-suspended heel enhance ski flex for more precision and control.ELASTIC TRAVEL: More elastic travel results in more reliable retention to keep you in when you need. LOOK bindings boast the most lateral travel before release and the fastest re-centering, delivering superior shock absorption and reducing unwanted pre-release.MULTI DIRECTIONNAL RELEASE: All the LOOK bindings have a 3D multidirectional release which reduces the risk of injury in all the different cases of fall, even the combined ones. In addition, the boot sole is always under a constant pressure : this provides a better control and a better stablity when the skier drives his skis.SHORT MOUNTING ZONE: The shortest mounting zone of any alpine binding available provides less swing weight, improved response, and a deeper, rounder, more consistent ski flex.BRAKE WIDTH: 80 MM.