You can not find a better pressure transfer of any propellant than using stainless steel line. It's durable, completely safe, practically indestructible and should last you for the lifetime of any marker. If you're adding a regulator or expansion chamber to your marker, chances are you'll need a different length line. These stainless lines have an American standard male 1/8"NPT threaded coupler at both ends. We offer you a choice of lengths to suit your needs at a competitive price. Please choose the length you want from the dropdown above before ordering.