No need to buy an entire set of dumbbells and an oversized dumbbell rack if you are a home gym trainer. This ingenious space saving design is the equivalent of 28 pairs of dumbbells ranging from 5lbs. to 85 lbs.each. Now you can instantly change the weight of each perfectly balanced dumbbell by simply moving a pin. This is one of the most useful innovations for home training to come along in years. An extra heavy set is also available with dumbbells going to 125 lbs. each. or a lighter set - 5 to 45 lbs. Powerblock dumbbells are also great for traveling - carry them in the trunk of your car along with the companion folding travel bench (click through to the Powerblock Main Page below). Setup up an instant gym in your motel room or even at a highway rest stop. (This was my only way to workout when I was an over-the-road truck driver. - Eric)