It's a 1955 Automatic K-351.  This model was made for four years but you don't come across it very often.  That may be because it has a solid 10K gold bezel with a stainless steel back and was more expensive than other K-models from the period. Like most K-series models, the K-351 has a 17 jewel Hamilton 661 movement inside. Running and seems to keep descent time tho no accuracy is guaranteed. Was a presentation watch and is personalized. The person that the watch was presented to was from the Milwaukee Wisconsin area and worked in the laundry delivery and sales dept. The dial has age and 10k gold case is in nice condition with minimal wear for a 1955, has a small ding on the side about the 8:30 position. Newer (not vintage) used Hamilton strap, can easily be swapped for a 18mm strap of your choice. Although in very nice condition for a rare Hamilton watch I offer no warranties as I did not service the watch and have no service history. nothing else included. if you have any questions please ask. as is