All models feature: Auto Tension Adjustment Concept for easy engagement and dependable release, Sensor Elasticity Tuner for adjustable sensation of float, 10 degree rotational/6mm lateral float, 13 or 17 degree release, self-cleaning double sided step in with wide entry area. XS Titan Carbon: carbon reinforced composite body, Ti spindles, aluminum spring axles. XS Carbon: carbon reinforced composite body, stainless spindles. XS: composite body, CrMo spindles.