The Ventline Vent Dome Operator Assembly replaces the lost or broken operator and knob on your Ventline Ventadome RV roof vent for motor homes and enclosed trailers. Properly sized mounting screw is included. Works with Ventline Ventadome roof vent model with flat metal dome (V2110). Also works with Ventline pre-2008 trailer roof vents with old-style, rounded, plastic dome lids (V2094). Arm measures 6-5/8". Works with Ventadome flat metal dome (V2110) Also works with Ventline pre-2008 old-style, rounded, plastic dome lids (V2094) Arm measures 6-5/8"" | Ventline BV0115-04 Ventadome Replacement Operator Assembly with Crank Handle