Three "wing tip vents" are supplied with the kit. Mike J and Nick informed me that the third is used to connect the fuel line across the firewall.
The wing tip vents are flared at both ends. The flare helps to hold the rubber tube on the inboard end. The flare on the outboard end should be cut off to provide the 45 degree angle into the airflow on the front side. This also allows the hole in the wingskin to be smaller.
The hole in the wingskin has to be angled slightly toward the trailing edge on the outside to allow the baseplate to sit flat against the inner skin surface.
