Vacuum System Accessories Vacuum Hose Barb Fittings Item #: A3812B These smooth single barbed are designed exclusively for vacuum and are not suitable for compressed air. Multiple barbed versions can handle both vacuum and pressure. Item No. Description Vacuum Hose Clamps for Hose A3812B Hose Barb, 3/8″ NPT X 1/2″ (12.7 mm) Hose