EnviroCare Replacement Vacuum Bags for Modern Day 12 Gallon Central Vacuums 3 Pack 3 EnviroCare Replacement Vacuum Bags for Modern Day 12 Gallon Central Vacuums Desgined to fit: Model: MD (Modern Day), Silent Master, Air Force, AirFlow CFM, Stor-Vac Fits #: E, E2, QE2, E3, QE3, G23, SV, and SVT, S1, S2, S3, S4, S44, S5, SP2, SP22, and SP3, open bag units over 34 inches in total length Fit with or replace genuine original (OEM): #721, Replaces older #721-5 & 721H. This bag fits over the blue cloth support. The bag was designed to be big so there would be more area to filter the air. After inserting the bag, open it up inside the vacuum by pushing down and out from the sides. Dimensions: 24 1/2" x 15" Bag Size with an elastic band at the top Bag Diameter stretches to approximately 28"