CK TS300 Trailing Shield Clip OnUse With 17, 18, 26 Series Tig TorchesWhen welding with metals such as Titanium, a secondary inert shielding gas application is necessary to protect the cooling weld bead and heat-affected zone.TS300 Trailing cups prevent oxidation by shielding the weld from the atmosphere until it has cooled to a safe temperature.