The Gruen N510R watch movement, commonly designated as 203, features various bridge shapes. It functions as a manual wind movement, equipped with a sub second function. Additionally, it utilizes a pusher at 10 o'clock to set the day, a pusher at 4 o'clock to adjust the date hand, and a pusher at 2 o'clock to set the month (only manually). The movement includes a date hand and a calendar feature. It was predominantly used during the approximate period of 1950.