To ride aggressively, you need strong tunnels that can handle your every move. The Ski-Doo Tunnel Reinforcement accessory provides extra support and boot traction, adding strength along your running boards. Machined aluminum extrusions allow you to dig your feet in. Protection & Coverage Additional strength and traction along the running board. Provides more support and boot traction for aggressive riders. Materials & Construction Machined aluminum extrusions. Colors to add some style. Installation & Hardware Compatible with tMotion Adjustable Limiter (860201861). Does not fit with Remote Limiter Strap Adjuster (860201855 and 860201496).