Part #012-978   Female Din to 1/4 NPT - $39.99
This is a female din (same as scuba tank) to 1/4 NPT. This adapter is used for mixing whips and use with large oxygen cylinders for emergency oxygen.

Part #018 986  Scuba Block to 1/4 NPT -  $29.99
This is Yoke Scuba Block to 1/4 NPT. This adapter is used for mixing whips and use with large oxygen cylinders for emergency oxygen