Up for sale is a rare Seiko Tomony 5018-7000 "Jump Hour". These models were made only in one year, 1977. 
 
• Case size is 35x35mm.
 
• Lug width is 20mm with a thickness of 13mm.
 
• Housing 5018 movement, which is just a simple hand-wind movement with no hacking. Service history is unknown, but it is currently running at +15s/day with an amplitude of 230.
 
• Original crystal is in good condition; however, there is a light scratch on the right side, near the logo, but it is hard to see since it lines up with the curve of the crystal.
 
• Original dial in good condition, no flaws.
 
• No idea what the case is made of, but it feels like plastic to me.
 
• No box or paper. Come with a NATO strap, as the picture states.