Zippi- I hope Tom doesn't get angry with me posting this, but here's what he said on another site when someone asked that question.

"It means that the plane uses CA hinges, and they are already installed in one side of the control. Slots are cut in the other side.

For example the hinges are glued into the rudder and slots cut in the fin. So all you have to do to hinge the rudder is slide the exposed side of the hinges into the mating slots and drip some thin CA on the hinge. This takes about a minute to do.

I can do all the hinging and install all the control horns in about 10 minutes maximum.

TF "