Made from premium low odor rubber, our dumbbells are a classic rubber coated hex dumbbell design that is quiet and easy on your floors. The chrome plated handle is straight and fully knurled for maximum grip. Unlike slippery ""ergonomic"" handles that only have knurl across part of the handle surface, our full knurl gives you a secure grip on the dumbbell at any weight. This feature is usually only found on premium ""pro-style"" dumbbells costing more than twice as much. Rubber Hex Dumbbells vs Adjustable Dumbbells More convenient and durable than an adjustable dumbbell set, a rubber hex dumbbell set can last a lifetime and is a great investment in your health. A rubber dumbbell is great for a huge variety of exercises, and never goes out of style. A staple in many strength and conditioning programs, dumbbells allow you to develop real world strength by moving heavy objects in your hands. It doesn't get any simpler. Handle diameter is 28 mm at 5 to 20 lb weight, and 34 mm at 25 lb and above. The thicker 34 mm handle adds comfort on heavier weights. Dumbbells heads are securely attached via press fitting and welding. Lifetime warranty for home use. 3 year commercial warranty.