XMark Fitness Vinyl Coated Kettlebell Set XMark Premium Solid Cast Iron Vinyl Coated Kettlebell - 105 lb. Set - (5, 10, 15, 20, 25 and 30 lb.) These one-piece solid cast iron kettlebells are hand crafted and coated with a tough premium vinyl. The rounded handles have spacious openings fitting comfortably into the palm of your hands. To reduce costs, we've also packaged our most popular kettlebells in sets. You will not regret purchasing XMark kettlebells. Thank you for choosing XMark.