Dorje,Vajra-3.5" antique brass
This is a rather small vajra, or dorje in Tibetan. It's still effective for wielding a thunderbolt however. That's what vajra means, thunderbolt. It also means diamond, meaning hard or indestructible.
The bell and the dorje are used together in Vajrayana Buddhism, which is part of the greater vehicle, Mahayana Buddhism.