Product review (5 stars): Where have you been all of my life?
The best idea ever! The space behind a dryer is usually very limited. With this elbow, you can make all of your hook ups to the hose and the house. Then, when you hook it up to the dryer, it has a tight friction fit that just pushes on and seats tightly to the dryer without clamps(you do have to clamp the hose end). This elbow also has friction joints. No matter what position the hose is in, the friction joints move to keep all torsional stresses off of the exhaust hose.  Then, this "hard" elbow won't crush or collapse. It's a hard stop to prevent the dryer from crushing the exhaust hose. Someone actually did their homework on this one!