The Rn2 Radon Mitigation Fan is the standard for Radon Mitigation. Works well in most situations. External wiring box for ease of connection. Waterproof gasket on wiring box. The Rn2 replaces model HP2190. Includes fan install kit. Choose coupling size and color to fit your mitigation system. Fantech Rn2 has a 4" output. Kit also includes (1) one manometer and (5) five system labels.