Alpha v2 dumbbells use a high quality rubber that is low oder. high quality commercial grade handles with steel core heads. This set includes pairs of 80, 85, 90, 95 and 100s. these are not your typical hex head dumbbell with cheap cast iron core heads under the rubber that get loose after a few drops. these are round steel core head dumbbells with 5 layers of rubber to make them have the hex shape.