This is a tremendously heavy piece of cast iron, 21" long. Dunno, 10 kg.? I haven't got a scale upon which to weigh it. The hole at the end is small on one side and ragged on the other. Not sure why. This'll go into the recycle steel bin unless someone wants it... Whoops, found out from several intelligent fellows that this is a counterweight for an old style window, hidden in the sash. Learn something new everyday!