This is what you call a busker cap, basically a baseball cap which has a pillbox shaped crown rather than the normal domed crown.
This was Christmas present which I yet to wear other than in the photos here, its always a problem when you have more than a few hundred to choose from.
The lemons also came as Christmas gift the same year and seem to go with the very colourful hat, also suiting the colourful top I'm wearing.
