The bottom, or "host" torch is a Mid Range Burner, which is a surface mix torch, allowing you to work both soft glass or borosilicate. It has a flame that ranges from needle point up to a one (1) inch diameter. This has a premix top instead of a surface mix top which means that the propane and oxygen are mixed inside the tip instead of outside.
THE PREMIX TOP IS DESIGNED FOR WORKING BOROSILICATE GLASS ONLY.
Uses 1/4" hose.