What equipment is used to refill the TMU-72 with nitrogen or argon?

The GCU-30 Recharging Unit is specifically designed for refilling the TMU-72 with nitrogen or argon. This piece of equipment is equipped with the appropriate valves and connectors necessary for safely and efficiently charging the TMU-72 system with the required gases, ensuring proper functionality and safety during operations.

The GCU-30's capabilities allow it to handle the pressures and conditions necessary for refilling, which distinguishes it from other equipment. While there are various devices used in the field for different refilling and charging tasks, the GCU-30 is the one that matches the specifications needed for the TMU-72, making it the correct choice for this question.