The MFN series heating tips fit the Victor® 315C, 310C, WH350, HD 310C, HD 310R torch handles and the 320 torch extension. The nut on this tip is 7/8" ID. It is designed for use with LP, propane, or natural gas. This Victor style 12-MFN has 8 preheat propane holes that are recessed from the outer edge of the tip to hold the propane flame. All our Victor® style LP heating tips listed include the mixer as shown in the photos.