The Series fresh air vent seals glue to the bulkhead with weather strip cement and requires training for the vent to close properly. Training consists of shutting the vent completely and leaving it closed for a month or two until the seal is compressed along the edge of your vent. Initially this requires a person pushing on the vent from the outside to get it to close completely. Once the seal has formed around the edge of the vent it will close easily. An alternative is the Defender style seal (order no. 369055) that glues to the underside of the vent lid. This seal looks different than the Series seal and if replacing an old original seal touch up paint will be required.