This glass heater cover is compatible with Arizer Extreme Q and the V-Tower. It’s a replacement cover for the one that comes with the box when you purchase either of the two products. To be clear, this cover is the glass piece that you can find within the vaporizer where the Cyclone Bowl nestles. This doesn’t refer to the heating chamber itself. If you find the glass that surrounds the ceramic heater is cracked, this cover is the replacement. Instructions on how to install come with the purchase. However, the glass heater cover is only compatible with the newer models (from 2010 up) of the Arizer Extreme Q and V-Tower.