Makro Teknik’s flanges are produced for maximum robustness, tightness and easiness of assembling at air ducts applications. Galvanised steel in line with TSE 820 standart is used at production. Non liquid, not frozen butyl mastic for tightness, is injected to suture where duct is placed. At design of 20-25 mm flanges additional measures are taken to seal. At flange diagram, it is shown connection types, air duct and flanges assembling methods at diagram according to DW 144 – EN 1507 standarts.