The Sonex, Waiex and Xenos are a family of lightweight, metal, low-wing, two seat homebuilt aircraft. Kits are produced and marketed by Sonex Aircraft, a small manufacturer based in Oshkosh, Wisconsin. By 2014, 500 customer built aircraft had been completed.The Sonex can also be built from plans. The Sonex, Waiex and Xenos all qualify as American experimental light-sport aircraft (ELSA).