Original Manufacturer's replacement bag for central vacuums: AstroVac: H1P, P70, SR36, SR38, SR52H, SR760, P80, H2, P73, P75, MK-IP, & MK-XXIIIBP. Valet: ATQ300. Vacumaid: GV30, GV50, GV30PRO GV50PRO. This bag can, also, be used in any central vacuum with a HPB1 paper bag. 1. When your current bag is full, simply lift the lid and remove it from the bag inlet fitting. 2. Throw away the used bag. 3. Replace it with a new HPB2H HEPA Filtered Bag by sliding the cardboard/rubber seal over the bag inlet fitting.