The Scandinavian style flies can be tied on just about any style of tubes. They are sometimes called fatbacks or temple dogs and are characterized by a very high wing on top of the tube. The tubes you got are probably just marketed that way. You can tie any style of tube fly on them. Some of the colored ones give you a very cool effect at the front of the fly. The exposed part of the tube sticking out of the head usually has an iridescent glow to it. Check the link below for some more info.