Class A Customs 74112V-C2G1 Heng&rsquo;s 12 VOLT Vortex II Vent Installed - Smoke Lid - 1&rdquo; Garnish Hengs 12 Volt Vortex II Fan Installed in Standard RV Roof Vent with Smoke Lid 1 Inner Garnish / Trim Ring Heng's Part # 90090 NO MOUNTING HARDWARE you must provide caulk/putty and screws ROUGH CUT-OUT OPENING DIMENSIONS (this is the hole you will need in your roof) 14 1/2 X 14 1/2 EXTERIOR MOUNTING FLANGE DIMENSIONS (sits on the top of your unit) 16 1/2 X 16 1/2