A locking option for those who (1) own a vehicle with factory tracks (2) want a rack system that's actually useful. These new licking towers pivot to adjust to the different angles on vehicles, so they wont tweak your roof. They slide onto, then lock down on, a base plate for easy on/off convenience. Two styles for fitting most vehicles that have factory tracks; easy installation; compatible with Yakima tracks; low profile design; 4 to a set; lockable with SKS cores.