The powerblock sports 90 stage 3 add on kit is designed to expand a stage 1 and 2 sport 90 to 59kgs 130lbs per hand and guarantees effective free weight training this add on stage to sport 90 stages i and ii helps to gain more strength tone the muscles and reshape the body the sport 90 with all 3 stages replaces 37 pairs of dumbbells or 2186kg 48193lbs of free weights