Mountain Standards: IFMGA/AMGA guide Mike Lewis tested the heavy yet durable Trango Cirrus helmet. He writes: "I have first-hand experience of working for a guide service that made the mistake of purchasing a full fleet of lightweight helmets, many of which didn't make it through the first month. The Cirrus is an excellent choice for program use.... The Cirrus is built not only for top impact, like most climbing helmets, but also for side and rear impacts as well, making the Cirrus a viable option for ski-mountaineering.... Expedition mountaineers, riggers, and other users will appreciate the toughness of the Cirrus as well." Five stars.