Quick Connector for Vacuum or Air Pressure. This quick connector includes both the base and the nipple. Each has a 1/4" NPT Female Fitting. The photo shows a barb fitting. This barb fitting is not included but could be added for an additional $1.90. This is a high grade connector. Industrial grade and can be used to hold vacuum. Either side can be purchased separately. You could put only the nipple on a vacuum fitting and it will hold vacuum. The nipple will seal vacuum/air pressure and when the connector is together the vacuum/pressure will flow.