The Thule Snowcat is a dedicated ski and board rack system that attaches easily to your factory installed side rails. The Snowcat holds 6 pairs of skis or 4 snowboards. This self-contained rack system adjusts to the width of your vehicle(s) with ease and keeps your gear safe with the included Thule lock cores. No additional parts are needed for the Snowcat: It's ready to go straight out of the box. Bottom Line: Open box, slap on rack, go ride.