The Torrid Air Cap has been upgraded to support a better pull through the Torrid Electronic Nail. On the first generation Torrid E-nails, there is a air hole on the side of the clear cap that helps with the pull of air through the triple coil into the water pipe. The new clear cap has a hole at the top so the air is more direct onto the triple coil. In the diagram below you can see on the old torrid clear cap the air entering through the side hole would go below the enail. Where the hole at the top opn the new clear cap the air goes right through the enail for a better and denser draw.