Price: 24.99
Product ID : R18
R18 Single Hole Round Ceramic Insulator, OD (in)=0.156, ID (in)=0.093
Description
More details on associated web pages:
Single Hole Round Ceramic Tube Insulators
The tubes are constructed of a pure 99% alumina ceramic that has superior gas and vacuum tightness and excellent insulating properties even at elevated temperatures.Ceramic Tubes
(Catalog A58)

The tubes are constructed of a pure 99% alumina ceramic that has superior gas and vacuum tightness and excellent insulating properties even at elevated temperatures.

Are available in both quartz and ceramic.