Cast aluminium, makes ball 4.36 kg /. 9.6lbs . easy to use. tracking provided for postage . Stainless steel 2mm cable is easy to use .125mm in length bends easy Put the 2 halves together and poke in the hole .Be very careful pouring such a large weight .Place in a bucket of sand is what I recommend .If held in a vice the mould can easily tip sideways. Bunnings sell the cable or online .