The Zodiac Seawolf is a classic, and starting to be very hard to find cheap!!! Even poor examples are going at $200. I measured mine, Seawolf, World Timer, Aerospace GMT (all same as Seawolf) with a very good Brown&Sharpes caliper. .6875 to .6930 so about 17.5 to 17.65. 18mm bands seem to fit fine. J B Champion is the most known band maker, then Kreisler, some debate about Drema in the later real Zodiac watches. My original bought new by me Yellow racing Bezel Seawolf has a Zodiac marker Oyster style strech band like Kyles, but is only marked Zodiac USA. Zodiac is on the clasph however and it is the original band.