festa amg radon fans festa amg maverick ecs radon fan - 4" installation kit - speed controllable - quiet and energy efficient radon mitigation inline fans - electronically commutated motor- high performance 4" duct fan maverick ecs 4x4 is up for auction in Tools & Home Improvement. The current bid is $1.50, 100% below the $320.00 MSRP, in As Is condition. This auction has ended — similar items appear in live auctions regularly.