RadonAway GP501 Radon Fan & install kit: two 3"x3" black Couplings & U-tube vacuum gauge & radon system labels We use this high suction fan kit to fix hard to mitigate homes with clay or sand under the slab. Fan: Radonaway GP501 with 5 year warranty, 3" opening, 70-140 Watts, 4.2"wc @ 0 cfm, 1.0"wc @ 95 cfm Kit: 2 couplings, U-tube manometer & label, System label, 3 Component labels, Homeowner brochure Fan is ETL Listed for indoor or outdoor use, and it mounts on duct pipe or with integral flange Fan has built-in electrical box that you can connect to house wiring or to a plug in cord.