This Francis Barker & Sons M73 compass was purchased by the Indonesian Amy. ( TNI AD = Tentara Nasional Indonesia Angkatan Darat.)

 A new feature on the M-73 was a reinforced hinge in which the pin was a predetermined breaking part. A former head of Barker (Mr. Leach, who also designed the L1A1) explained that the Australian soldiers used to test their strength by holding the lid in one hand and the case in the other and break the connection with a single twisting movement*. For this reason Barker developed a new hinge fixed by screws instead of a brazed tab.  On the back the compass is  marked only M-73 PAT. APPL. . The protection grid of the sighting window was also reinforced and attached by screws and threaded bushes.