The Yakima Base Line Towers are designed for use on vehicles with a naked or bare roof and are part of Yakima&';s new Stream Line roof rack series. The versatile Base Line&';s intelligent design and advanced adjust ability help it morph to the shape of your car&';s roof for a sleek, secure, load-it-up fit. Sold in pairs or sets of four towers. Features: Designed for use on vehicles with a bare roof Used in combination with either Yakima Jet Stream Aero Bars or Yakima Core Bars, sold separately Can also be used with Yakima Round Bars by purchasing the 203536 Stream Line Round bar Adapter Kit Toe adjustments also change the angle of the Base Line Towers for a perfect fit on vehicles with scalloped roof shapes Prevent theft of your roof rack by adding a Yakima 4-Pack of Locks, sold separately The Base Line Towers feature Yakima&';s unique bi-axial Drop Hook clip adjustment to ensure a custom, secure, and streamline fit Bar Bed Pitch Adjustment allows you to easily adjust the pitch of the crossbar to keep them level on vehicles with a curved roof line Base Line Towers are attached to your vehicle using vehicle specific Yakima Base Clips, sold separately, two pairs of Base Clips are required for a two bar roof rack system Increased load capacity compared to previous Tower generations from 165lbs/75kg up to 220lbs/100kg. Load capacity varies by vehicle. Please see Yakima Fit Guide for your vehicles recommended load capacity. Covered by Yakima&';s Limited Life Time Warranty A pre-calibrated torque driver is included to ensure you tighten your rack to the exact level of tension Set of 4 Base Line Towers