The S121 is a comfortable waist belt that fits up to a 44in/1.1m waist with two 2-ft/60 cm tubes and two 2.5-ft/76 cm of adjustable nylon fasteners with clips on each end. Available in green resistance level (8-24lbs/3.6-10.8kg of pull*). Sold as a single unit. Not interchangeable.
*Resistance when stretched 1-3 times original length.