Replacement Bellows Kit For S-Series Vacuum Pump; T-Series discharge pump; VGII. VGIII and J-Series Vacuum Generator. This is the “New” Style bellows identified by the Gray colored shaft and puck. The Gray bellows is the only bellow Dometic currently makes. It works for all of the discharge pumps and bellows style Vacuum pumps. It’s highly recommended to change the O-Ring kit when replacing the bellows.