All of these are used. Looking at the photos you can see that son of them have some spots where they shorted even through the ceramic insulators. Other ones the ceramic looks to be intact, but I'm not sure how reliable they still are. They could probably be rebuilt or used for parts.The item "Lot of 10 USED Vacuum Feed Throughs Electrical Feed through As Is Untested" is in sale since Saturday, May 22, 2021. This item is in the category "Business & Industrial\Hydraulics, Pneumatics, Pumps & Plumbing\Pumps & Pump Accessories\Vacuum Pumps\Other Vacuum Pumps". The seller is "vova324" and is located in Concord, California. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Taiwan, South africa, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Israel, Mexico, New Zealand, Philippines, Singapore, Switzerland, Norway, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Chile, Colombia, Costa rica, Panama, Antigua and barbuda, Aruba, Belize, Dominica, Grenada, Saint kitts and nevis, Saint lucia, Montserrat, Turks and caicos islands, Barbados, Bangladesh, Bermuda, Brunei darussalam, Bolivia, Egypt, French guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Jordan, Cambodia, Cayman islands, Liechtenstein, Sri lanka, Luxembourg, Monaco, Macao, Martinique, Maldives, Nicaragua, Oman, Pakistan, Paraguay, Reunion, Uruguay.