This extended back cap is designed specifically for WP9 and WP20 series TIG torches. The additional length accommodates longer tungsten electrodes for specialized applications. The brass body provides excellent thermal conductivity to prevent overheating. The knurled grip ensures positive handling even with welding gloves. The precision threads engage smoothly without cross-threading. Ideal for reaching into deep joints or working with extended electrodes. Maintains proper gas flow characteristics despite the increased length. Compatible with all standard collets and collet bodies for these torch models. Helps maximize electrode usage by allowing full-length insertion.