At the time of Sonic Adventure 1, a company called "E Watch Factory" decided to do some SA1 themed watches. You could supposedly mix & match the band colors, numbering style & character who you wanted, so you could compose, and then order your own special watch design, and they'd send it to you.

Does that whole "mix n match any character" theme sound familiar? It should! It's directly from the "Avoiding Bootlegs" section of the site. What's the difference? Quality...most likely. E Watch Factory was a licensed company, they were just using a common/familiar bootleger's technique to create their products. (Really, the 'faces' are just special print outs...)

The idea was sound, it's just fakers have sort of turned it to trash in the meantime. You can see they really went all out with the details. You could get Sonic, Tails, Knuckles, Rouge, Eggman, E102 Gamma, Chao & Big. The numbers could be regular, triangles (no numbers) lines, seconds (to 60, increments at either 20 or 5) or tiny numbers (Rouge's) Likely the E & Eggman watches are least common...however all of them are pretty rare anyway. The campaign was only somewhat-promoted, and it's thought they were also a bit costly.