The Gruen 587 watch movement is a manual wind mechanical movement. It features a small seconds sub-dial, a chronograph function with a central seconds hand and 30-minute counter, along with a date function. The movement has a power reserve of approximately 45 hours and operates at a frequency of 28,800 vibrations per hour. It is comprised of 25 jewels and measures approximately 13 lignes in diameter. The movement is of Swiss origin and is renowned for its precision and reliability.