Third collaboration for Charlie Hunnam and Ron Perlman. Perlman and Hunnam worked together on the critically acclaimed FX series Sons of Anarchy (2008-2014) and Guillermo del Toro's sci-GI action adventure Pacific Rim (2013)
Charlie Hunnam and Chris O'Dowd play American brothers in this film, but ironically, Charlie is English and Chris is Irish.
There is a character in the film named Cholo played by Frank Alvarez, a pivotal character in Charlie Hunnam's and Ron Perlman's television series Sons of Anarchy (2008) is named Marcus Alvarez played by actor Emilio Rivera.