Mullite Thermocouple Protection Tube - Unit is 5" Long x 1" Diameter with a stepped head for use with All Standard Length Type-K 8 Ga. Thermocouples. NOTE: This is the newer type open end tube which was put in service with new kilns starting in September 2020.Type-K 8 Gauge Thermocouple (Exposed) with Ceramic Terminal Block - Ceramic tube is 4" Long x 1/2" Diameter.

The old, closed-ended protection tubes have been discontinued and are no longer available

IMPORTANT NOTE: 

If you have the old closed-end tubes and you are changing one tube you need to change all of them to the new, open ended type.

You MUST ALSO change the thermocouple offset to 0 for all zones. (see your kiln's manual for instructions on how to do this)