impeller light weight,well-set,smooth , low noise .impeller 's diameter and long can produce according to clients' request. 1 impeller s long size and diameter can produce according to clients request . the standard diameter is :30mm. 45mm, 48mm, 60mm, the long size :180mm. 240mm, 300mm. 360mm etc .2: cross flow impeller material is aluminum .3: wind wheel can be use in cross flow fan, blower etc ...