Even though Kingsbox weights are cheaper, it does not mean that their quality is questionable. On the contrary! They are made of high-quality rubber, which guarantees a long life. The rubber is combined with a stainless-steel insert. The diameter of each disc is standardized (450 mm) according to the IWF standards.The 5 kg discs are not designed to be thrown freely on the floor, but must in anycase be put down in a safe manner, thus preventing their damage.Disc thickness:10 kg: 40 mm15 kg: 63 mm20 kg: 78 mm25 kg: 96 mmWarranty on Outlet products.The specific difficulties of the purchaser with the outlet products of the company KingsBox d.o.o. will be treated individually, case by case.You can not return products from outlet category.