Mad Rock's Mars 4. 0 Harness is a top-level all-arounder for any rock climber whether you're tying in at crags or the base of a desert tower. This generation uses less padding than previous Mars harnesses and instead utilizes an innovative webbing technology that better distributes your body's weight without disrupting the harness's overall safety. For you, this means that the harness will pack easier, feel comfier, and perform better on the climb.