WARNING: Do not use any non-Aithre fittings on your oxygen bottle as the fittings Aithre provides are special high-pressure fittings designed to withstand 3000 plus PSI. Many store-bought fittings are often only rated to 100-300 PSI, which is not sufficient.
The Altus Meso is installed to existing oxygen bottles using a provided T-fitting. For some bottles, however, there exists a wide shoulder that prevents rotation of the T-fitting. This M-F 1/8 NPT extension is used for these situations to provide clearance to and enable installation of the t-fitting provided with the Altus Meso.