Glass-To-Metal Bonding Technique Insures No Leaking Between Feedthrough Connector And Inside Of Transformer Tank; Glass-To-Metal Bonding Eliminates Need For Epoxy Bonding Or O-Rings, Which Require Maintenance And Tend To Fail; Hundreds Have Been InstalLED Over Time With Not Even One Reported Leak; Made Standard With 1/4 Inch Npt Male Bulkhead, 18 ANSI Threads Per Inch; Enables Probe Installation Without Carrying Bulky Mechanical Weight At Probe End; Reduces Chances Of Probe Breakage During Installation; St Type Connectors Resist Failure Due To Vibration; Designed Specifically For Oil FilLED Or Dry-Type Transformers; Can Be Mounted On Any Part Or Location On Transformer; Survives Full Vacuum Or Pressure (Up To 200 Psi)