When California took weights out of the State Prisons, inmates were furious. Lifting weights was not only for self defense in the difficult prison life, but also an outlet for stress.
This biceps exercise was formulated by Kali Muscle before the weights were taken out. Kali had anticipated the weights being taken out so he thought of an alternative exercise for the barbell curl.
See sequence below for exercise, as well as video. Photos and video courtesy of Justin Cruz and Arash Baboo of StrengthProject.