This is a Longines Conquest hi-beat watch. Hearing this watch tick, it is definitely a high beat movement and I believe it to be a 431. The serial number if 16.85 million, suggesting that it was made after 1970. I strongly suspect that at some point, there was a problem with this watch and the owner set it aside, which accounts for the condition. Case: The case is 34mm across without crown at the widest point. Because of the shape, it looks a little larger. The case is in good condition for its age although it has some scratches and a handful of minor nicks. Crystal: The crystal may be original. It has a small imperfection near the center. Movement: The movement is high beat likely 431. It runs. However, I can tell how well it tells time (see below). Dial and Hands: The dial is vertically brushed and is striking. It looks in excellent condition. The Longines logo itself has some discoloration. The hands are in overall good condition. However, the seconds hand sometimes sticks to the minute hand and can be released by gently moving forward the time. Crown: The crown is signed. Strap and buckle: The bracelet is signed and I believe it to be original to the watch. It fits my 6.5 inch wrist. Price: 480 USD (or best reasonable offer) including shipping to the Continental US with USPS insured . International shipping a little extra. The watch is in Los Angeles. I purchased a watch recently where the seller provided the watch at a fraction of the retail value and included a very expensive service. I would like to pay it forward. If you are interested in any of the watches I have for sale, please do make me an offer - I will do my best to accommodate.