Greenwood inline silent fans are 70% quieter than standard axial fans when operating. The fans are designed to offer an effective, safe ventilation inline ceiling solution. This type of installation requires a more powerful motor as the extracted air will usually have further to travel than a standard through wall installation as it is typically fitted with the duct running in a loft space and out through the soffit. The SRD100 runs with 70% less noise than conventional fans. The product is ideal as a replacement fan for an existing inline installation.Includes mounting bracket.