• Malone Specialty Inc. offers a Carbon Steel Metric Tube Reducer to Female Swivel with an O-Ring as well as a 316 Stainless Steel Metric Tube Reducer to Female Swivel with an O-Ring, in most metric sizes. These Tube Reducers conform to DIN 3859-1 specifications. This Metric Adapter comes complete with one Metric Tube Nut and a Metric Tube Sleeve, and uses a bite type style connection. For more information see below, or contact one of our experienced salesmen at (440) 255-4200.