The Double D thermoplastic cup is a favourite amongst TIG welders. For their extreme gas coverage even with your tungsten way out. These thermoplastic cups are basically unbreakable, making them a worthy investment for any welder.*
Suits a WP-17, WP-18 and WP-26 Torch head and 2.4mm tungsten.
It is important not to over tighten these cups as you can warp and break the thermoplastic, only a small amount of pressure is needed. Also a recommended maximum amps of 175DC and 25LPM or more. To prevent the tungsten from arcing on the brass gas lens, keep the tungsten sharp and clean.
*Yes, these cups can still break, but they are way stronger compared to ceramic and Pyrex cups. It will take ages to go through these.