Rinnai Burner Cap 【151-403-000】 for High-Power Burner (Gray) Set of 2 This is the cap that sits on top of the burner, where the flame comes out. I accidentally ordered the wrong model. It is a genuine, new, unused product, but I opened the box and tried to install it once. At that time, it got a slight scratch (see images 4 and 5). Only sold as a set.