This unique set is designed to melt between 2 to 6 ounces of gold. It can also be used with silver, copper, aluminum, brass, and other precious metals. Requires 2 standard propane gas bottles (not included). Please note that this mini kiln is not recommended for smelting ore concentrates, due to the limited capacity for both cons and refining flux 1 to 3 ratios.Also Includes:(1) Pair of Stainless Steel Small Ring Tongs: Measuring at 13" in length, these high-density stainless steel tongs can handle the Mini R-9 crucible cups with grooves, as well as crucible cups with a base.(2) R-9 Graphite Crucibles: Designed with a pour spout for easy pouring.Please contact us with any questions. Thanks for looking!