The anaesthetic techs dont want the cylinder hoses fitted with BS probes as in theory its possible to connect these to the wall and bypass the cylinders (althought its unlikely in practise due to the length of the hoses.
The new Draeger regs have a NIST fitting on the output so therefore use a NIST to NIST hose to connect to the machine. Oxylitre dont provide regs with NIST outlets.