The Yoga Tantras are the third of the fourfold division of tantras used in the Tibetan later-diffusion traditions. The main texts of the Yoga Tantras are the Tattvasamgraha Tantra and the Vajrashekara Tantra. The Yoga Tantras teach about the Five Buddha Families of the Vajra-Realm, and are focused on the Buddha Vairochana. Unlike most of the Highest Yoga Tantras, the Yoga Tantras were known in Tang and Song Dynasty China, and are still practiced today in Japan.