Vintage Gruen 401 420 Copper Dial Men's Mechanical Wristwatch 400 Swiss 10k GFProduct Description Item: Wristwatch Brand: Gruen Model: Copper Dial Reference: 401 420 Movement: Mechanical Case Material: 10k GF Country: Swiss Jewels: 17 Jewel Gender: Men's Caliber: 400 Size: 20. 5mm About the brand: Founded in Ohio Gruen was one of the largest American watch manufacturers for the greater part of the 20th century. In fact, shortly after their relocation to Cincinnati, Gruen became the number one selling watch brand in the US. Like