Use these non-conductive rubber endcaps to prevent hotspots from loop tails, seal tubing when not needed to connect with, etc. They fit fairly snugly but gluing them on for security is recommended. 

Comes in 3 sizes, to fit each of our 3 different conductive tubings.   Please note they and our tubing are measured by outer diameter... Important Sizing Note:  These endcaps go with the following Conductive tubing sizes:

4mm caps go with 4mm pin tubing

6mm caps go with 6mm tubing, either pin or banana 

8mm caps go with 8mm banana tubing