Shelter Structures America’s M-Series clearspan tent structure is Shelter’s middle-sized product for the U.S. market. The engineered M-Series has a standard 3-, 3.4- or 4-meter side height and a 5-meter bay configuration. The tent structure is available in 10-, 15-, 20-, 25- and 30-meter widths as well as customized sizes. The profile sizes measure 150mm, 200mm or 250mm and are all constructed with T6061/T6 hard-pressed aluminum extrusion. Available in both A-frame and arcum designs.