Silver prayer wheel bhum counter.

Bhum, pronounced "boom", is Tibetan for "100,000". Bhum counters can be clipped onto a mala to help keep track of the number of mantra recitations one has completed, either alone or in combination with a pair of counters. For example, you may use a bhum counter to keep track of thousands or hundreds of thousands of mantra by moving it along the mala, one bead at a time.