Greatly contributes to the SRViper's trail character. The deep (26mm depth) keel design is specifically developed to work with the SRViper models to keep the ski tracking straight and true down the trail, virtually eliminating nosiness and darting. With two keels that are 5mm deeper than the original standard Tuner Dual-Runner skis and a choice of runners (SMA-8JH31-01-10; SMA-8JH31-02-10; SMA-8JH31-03-10; SMA-8JH31-04-10, sold separately), riders can tune handling to their preference, resulting in excellent comfort and control. Sold individually. 2014 SRViper models require a Deep Keel Tuner Dual-Runner Ski Mount Kit (SMA-8KNVP-MT-00) for installation, sold separately.