Chenrezig, also known as Avalokiteshvara, the Buddha of Compassion, is the essence of the compassion of all the Buddhas.  With the infinite compassion for all sentient beings, Chenrezig is one of the most popular deities of daily practice.  Compassion is a cornerstone of Buddhism.  For Mahayana Buddhists, its is an essential quality that must be developed to attain enlightenment.  White in color, Four-Armed Chenrezig is the most common form of this Buddha.  One pair of hands, folded in prayer, holds a wish-fulfilling jewel, which symbolizes bodhicitta-the altruistic intention.  In his second pair of hands, Chenrezig holds a crystal rosary, signifying his ability to liberate sentient beings from cyclic existence, and a blue utpala flower, further demonstrating his pure bodhicitta intention.  The deer skin on Chenrezigs left shoulder is a symbol of his gentle nature as well as his skill in taming delusions.  By reciting Chenrezigs six-syllable mantra, practitioners develop their capacity to further open their hearts.  It is also said that the six syllables correlate to the Six Perfections of generosity, ethics, patience, joyous effort, concentration and wisdom.  The mantra for Chenrezig, perhaps the most recited mantra in Tibetan Buddhism, is Om Mani Pamdme Hum. 

Vajrasattva, known by Tibetans as Dorje Sempa, is who practitioners turn to for purification.  He is the essence of the indestructible pure and clear nature of mind of all the Buddhas.  Vajrasattvas white color is representative of his absolute purity.  In his right hand he holds a vajra, which symbolizes the method of compassion.  in his left hand is a bell, symbolizing the wisdom of emptiness.  Vajrasattva holding the two together represents the inseparability of these two spiritual qualities and the necessity for them to be used together.  Vajrasattva meditation practice is used by practitioners for purification of all levels of transgressions and is especially potent for the restoration of broken vows.  The practice employs the Four Powerful Opponents-in which practitioners generate a true sense of regret, refuge and determination not to repeat the action-and then take remedial steps to rectify the transgression.  The short mantra for Vajrasattva is Om Vajrasattva Hum.