Permits mixing of acetylene with air at the torch head, so no other source of air is necessary. Four interchangeable tips are supplied, producing a range of flame sizes from small to large, making it suitable for jewelry soldering (except very small work). and melting. the acetylene is stored in tanks as a liquid and only becomes a gas when valve is opened. Includes torch, handle, 4 tips, regulator for "B" tank and a 6' hose with fittings.