First off, let me say this air deflector does its job when it works. I installed it in my bedroom to stop that brutal direct AC blast that was giving me winter-in-July chills every night. The adjustable length (56cm-106cm) fit perfectly under my wall-mounted unit, and the multi-hole design really does diffuse the air nicely - no more freezing one spot while sweating two feet away.

The installation was stupid easy - just slide it into the AC vents. No tools, no fuss. I loved being able to angle the airflow upward in summer (cool air falls anyway) and redirect it downward in winter. My energy bill dropped about 15% last month because I could finally stop over-cooling the room just to get decent air circulation.

BUT - and this is a big but - the durability is questionable. Like another reviewer mentioned, the adhesive failed after just a day. Mine stayed up for about a week before the plastic clips snapped during adjustment. I ended up reinforcing it with packing tape (not the aesthetic look I wanted). The hollow waterproof design works fine, but the mechanism feels flimsy for regular adjustments.

Final verdict? Great concept with mediocre execution. If you need a temporary solution and don't mind some DIY reinforcement, it's worth trying - especially for elderly folks or kids' rooms where direct airflow causes issues. But if you want a long-term install, you might want to keep looking or be ready to MacGyver some fixes.