Chakrasamvara ?the Wheel of Bliss.? It is the highest class of tantra practice. Sometimes it is only called Samvara, which means ?collected together.? Not only Samvara it is also known by the name Heruka where ?He? is a Sanskrit word which means ?to act with a joyful way,? and second word ?Ru? is short for the Sanskrit word for blood. And ?ka? is a Sanskrit word for skull cup. Thus Heruka is ?the one who sports, or acts happily, with blood in the skull cup.?In Kagyu and Nyingma systems, Heruka is sometimes also used for male deities. The Cakrasamvara Tantra is usually dedicated to describing rituals and meditations.