Khan Academy: Thunderbolt and Bell

The vajra (Tibetan: Dorjie) and bell (Sanskrit: ghanta; Tibetan: drilbu) are the most important ritual objects of Tibetan Buddhism. Most every lama has a pair and knows how to use them. They represent "method" (vajra) and "wisdom" (bell). Combined together they symbolize enlightenment as they embody the union of all dualities: bliss and emptiness, compassion and wisdom, appearance and reality, conventional truth and ultimate truth, and male and female, etc.