its a water tight rubber strip. they came in 6" sections, so i had to loop three junctions together. i work in sales at a electrical distribution center so I got them as a "Demo"....from one of my vendors....hahah along with the track to mount them. but you can find the same idea on ebay for pretty cheap. you can look at a company called Elite LED lighting. i believe the website is
www.iuseelite.com they have ribbon led's that you can get. there a bit pricey, but that is where i got my track system from. take a look. at the very least you will get an idea of what it is and can probably find something simular to both the lights and the mounting track. if you get serious about it, you can let me know, and i can see what i can do for my cost and have it direct shipped to you. let me know. im new to this site, but i've already gained a ass load of info for DIY mods i want to do, so I'm more than happy to help out and contribute here.