There are (2) types of vents common on RV's. The one with (2) pivoting tabs (shown in the link listed above). It has 2 small (delicate) tabs that swivel out of the way and the flap is allowed to open. We switched about a year or two ago to the Endura vent. For this vent you pull down on the tabs (its more of a clip type set up). It is UV stable (so no yellowing) and the tabs are a little more durable....although they can be a bit tough to open the first few times.
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