Minden Tube.

Also - it always amazes me that most tube/box trailers are made just barely big enough to contain the glider. My 15 came with an old wooden monocoque type trailer when I bought it. Unfortunately the deteriorating fiberglass sheathing and the Pacific Northwest climate conspired to return it to nature pretty quickly because it actually functioned well. The fuselage went in nose first on a big stable dolly, the wings went in root first also on big stable dollies, the horizontal stab hing from the ceiling just like in a clamshell. The smartest thing the builder did was to make it roomy. There was actually enough room inside to walk from the back to the front with the glider inside (a little over a foot of clearance between the wing and fuselage). This meant that when moving the wings in or out you could hold the tip at the height that was best for your back and not have to worry about the leading or trailing edge scraping on the trailer or fuselage.

After it disintegrated I replaced it with a clamshell which is even better.