Well, I may be biased, but I class this as one of the best bitters around! Milwaukee Bitters, olive / amber glass, it is actually an Australian bottle. There are a number of American named Australian bitters, this is the second best one, the best being a cobalt Boston bitters which is a phenomenal piece of glass. This is the ONLY example known, there is another in green glass and there are two aqua ones. Enjoy!