Smith's Preset Regulators are for use with disposable 14.1 oz. and 16 oz. propane, mapp, and oxygen cylinders. Both regulators accept "B" 9/16" hoses. If you currently own a Little Torch connected to acetylene and oxygen tanks, you can also use it with propane and oxygen by purchasing these preset regulators, which do not require gauges. Smith advises that a flashback arrestor is not required for their Preset Regulators.