Specifications: -Gas type: Natural -Mixing Tube OD: 7/16" (11mm) -CFH*: 1.33 -BTU Output*: 1,365 -Overall Height: 3-1/2" (89mm) *Note: CFHs and BTU Outputs are figured on: 5 inch Water Column Pressures for Artificial and Natural Burners. 11 inch Water Column Pressures for LP Burners. Inlet OD for all Burners: 5/16" Serrated Humboldt's Adjustable burners utilize the same highquality die-cast bases as our Standard Burners, but provide a precision needle valve to achieve an accurate, adjustable flame. Refer to chart below for specific models and operating parameters, including standard and micro burners, as well as burners with flame stabillzers.