In its original wood case. Serial number 349049. The face is marked Chelsea Clock Co. Boston, US Army Clock, Message Center, M1.

The Chelsea message center clocks are thought to be the first dedicated Army Message Center clocks in the US, which went into production a few years before the start of WWII. A message center was a simply radio primary used for for orders and reports. Time was critical to radio operation as messages needed to be time stamped and logged when received or sent. Also, some radio operators were required to switch frequencies at specific times.

The Chelsea Message Center clocks were a variation of their maritime clocks and were designed to be reliable and easy to transport and set up in a variety of environments. The first clocks were brass cased like this one with later clocks moving to a plastic housing. Their fine and sturdy wood flip open cases with strap were both protective and convenient.