TheWolf Tooth Low Profile Shock Rebound Knobwas created to prevent catching of the rebound adjustment knob. If you have a Fox rear shock that is mounted under your top tube, removing your bottle from its cage can catch the rebound adjustment knob and change your rebound without you knowing. This can lead to a rear suspension that packs up or one that bounces around. The Wolf Tooth crew noticed this issue and decided it was time to fix it. The following brands have one or more models that could have this issue: Trek, Specialized, Cannondale, Pivot, Turner, Ibis, Yeti, Scott, Intense, Salsa. There are bikes from other brands that have this issue as well. If your water bottle is near the rebound knob, there is a very good chance your rebound setting is different than what you originally set ... More info