Filtex (or Filtrex) and others.
Replaces all Filtex bags about 18 inches tall and taller, and often referred to as the 7 gallon Filtex Bag, and Filtex Filter S-310. Top of bag has 1.25 inch round cardboard lip and 13.5 inch total outside diameter. (The variation over the years is due to changing bag manufacturers.)
Also fits some units made by: M & S.
Quantity of 1 = 4 bags. REPLACES MS VM502.