Feature : portable machine Beside 1kg melting furnace ,we also offer other option Capacity option : 2kg 3kg 4kg 5kg 6kg 7kg 8kg The more capacity The price is higher You can choose the best capactiy depend your metal size or feeding size For example , if you want melting 100 grams aluvial/sand gold ,1kg melting furnace is enough about input volage : we have two choice : 220v single phase and 380v three phase. http://www.jxscmachine.com