VF3503 shop vac replacement bags are compatible with certain Ridgid vacuum models. They are not suitable for vacuums that do not have a nozzle. The bags are made of double-layers of polypropylene for effective dust and particle filtration. They also feature a rubber sealing collar to prevent air or dust leaks. The dimensions of the bags when spread out are 31-3/4" Long x 11-3/4" High, with a 2-1/2" Fitting Diameter.