A gas lens sits in place of the standard collet body and uses a fine mesh to straighten the shielding gas flow into a smoother, https://bbarlock.com/index.php/Keeping_A_Stock_Of_The_Right_Tungsten_Types,_Collets_And_Gas_Lens_Sizes_For_The_Work_You_Do_Avoids_A_Lot_Of_Avoidable_Downtime,_And_It's_The_Sort_Of_Consumables_Range_Worth_Sourcing_From_A_Specialist_Supplier_Like_fabrication_Equipment_Supplier. more laminar stream around the arc.