I still use a set of Power Blocks that I got about 7 years ago. It adjusts from 2.5 lbs to 50 lbs. Their shape is odd at first and they can be tricky to get your hands in and out of but I love them. I have used them for traditional dumbell exercises, flipped them over and used them for close grip exercises, and even some kettle bell exercises. When they get over 50 lbs they start to get a bit too long for my taste, but I don’t travel with heavier weights than that.