This rather ordinary looking watch-cap is actually rather valuble.
This item was a pre-release give-away when you pre-ordered Shadow The Hedgehog the game through the Sega newsletter or through an Electronics Botique. The hats had an ok supply, just the "pre-buzz" against the game itself resulted in not too many pre orders. Soon after the game was released, the once 'free' caps were going for over $60.00 USD on ebay. Hang on to your hat if you've got this one!

With the right photo you can see the detail of the cap. It's the usual stretchy thick knit fabric that this watch cap type hat is usually made of. The logo & symbol are all embroidered, & likely sewn down so it's sturdy and good quality. The blue Sega tag on the top is a paper tag, & the plastic hook looks like its for retail/hanging, though they were never sold.