Amitābha is also known in Tibet, Mongolia, and other regions where Tibetan Buddhism is practised. In the Highest Yogatantra of Tibetan Buddhism, Amitābha is considered one of the Five Dhyāni Buddhas (together with Akṣobhya, Amoghasiddhi, Ratnasambhava, and Vairocana), who is associated with the western direction and the skandha of saṃjñā, the aggregate of distinguishing (recognition) and the deep awareness of individualities. Amitābha is the principal buddha in Pure Land Buddhism, a branch of East Asian Buddhism. In Vajrayana Buddhism, Amitābha is known for his longevity attribute, magnetising Western attributes of discernment, pure perception and purification of the aggregates with a deep awareness of the emptiness of all phenomena.