What is "namgyalma"

Since 1571 Namgyälma has been the namesake for Namgyal Monastery – the personal monastery of all the Dalai Lamas since its establishment by the Third Dalai Lama, Gyalwa Sonam Gyatso – Namgyälma is a female yidam and long-life deity of the Kriya Tantra class in Tibetan Buddhism. She is typically depicted as being white in colour, seated, and has eight arms, holding various symbolic implements in each of her hands.