The Crane Bell Company out of Osaka, Japan probably makes the classiest bike bells you're likely to find anywhere. The Karen bell is a simple design using a spring strike mechanism. A hollow dome is riveted to the central fixture of the bell. A bolt-shaped striker mechanism attaches to the same fixture via a spring. A flick of the spring and the striker will rebound against the dome causing it to chime. This model is copper. If you want some cool analysis of all the many Crane bell options we carry, check out our blog post on the topic, here. You can even listen to recordings of the bells there!