The Narrow Profile primary cover is standard equipment on 2015-2016 FLHTCUL Electra Glide Ultra Classic & FLHTKL Ultra Limited Low models and approx. 1" narrower than the stock cover on other 2007-2016 Touring and Trike models. It allows easier reach to the ground and is shaped to slim the bikes profile on the left. Installation requires the separate purchase of primary gasket kit and 2015 and later style derby cover.