The Storable Tubular Extendable Member (STEM™) is a unique product with over 30 years of space flight heritage including programs such as Voyager, GPS IIR, Hubble Space Telescope and Mars Pathfinder. These products are available as the most simple STEM mechanism or the smaller package of the BI-STEM™ or the Interlocked BI-STEM which provides improved torsional rigidity and allows longer deployed lengths.

STEM has been produced from 12 millimeter to 50 millimeter diameters and is manufactured in beryllium copper for antenna elements and stainless steel for structural applications.