Maha Bandha

Bandhi (“hold”, “tie”) are special locks that affect the physical body and heals it. These yoga exercises allow you to "control the various organs and nerves of the body."
Gheranda said: there are 25 Mudras who bring the yogi siddhi. These Mudras are as follows: <...> Uddiyana-bandha, Jalandhara-bandha, Mula-bandha <...> "(c)" Gheranda-Samhita ", 3.1