I purchase a set of these 5 lb . dumbbell to use with a couple of workout dvd 's I recently buy . they be wonderful . they neoprene make they easier to grab and the hexagonal shape prevent the weight from roll around when you place they on the ground . these weight be not design to help build a huge amount of muscle mass , but when add to a cardio workout , they do help with the muscle toning of one 's arm . I have have these weight for about a month now and really enjoy use they . I plan to soon switch over to the cap gray 6lb . dumbbell .