For the advanced user who wants to push their limits: the Ballflask Steel from Kiotos has an impressive weight of 1405 grams and is made of high-quality, shiny stainless steel. This robust ball stretcher consists of two parts that are easy to apply, with a metal cylinder that you can screw on for extra weight. Need more? Fill it with sand or add extra weights. This product is not suitable for beginners, but ideal for those looking for a challenge.