Custom made stainless hinges by self, the top lip springs both closed and open.
No shock cord or liens required.
The are not restricted by the vang in any way and you can launch a spinnaker from them (although with greater friction when open) while closed. And they are deep. Plenty of room for a new crunchy spinnaker and also a few water bottles as well. Weathermax sides, mesh bottoms and carbon re-enforced mylar top skirt for some show and shine.