Happ sells Marquee Retainers in 10-foot lengths. I don't know how it works so I don't know how many to order. do I just need one for the top and one for the bottom. That would be a little over five feet so I'd be fine ordering just one, but if I need one for each piece of lexan sandwiching my marquee I'll need four strips (top and bottom for each lexan piece) and so I'd need to order two lengths from Happ. I'm trying to research as much as I can before placing my Happ order so I can get it all in one order to save shipping, etc. but I haven't found any detailed descriptions regarding how the marquee retainers work. Help?