I found this product useful for travelers with luggage restrictions. Not all airlines let their crew to check-in their luggage and thus, many of us struggle to compress as much as possible. If you go to places where shopping is inevitable (i. e. Paris, Beijing), this product becomes very handy.I usually put all my spare uniform pieces and go out clothing in one big space bag and bring an empty one to layover.
This product is very easy to use: you simply put your clothes in the bag, zip it and roll it from one end to the other to let the air out. Your clothes will be compressed to at least half of the original size. There are many brands out there now, some come with a detachable zipper. Some also claim to be odour-free.
However, there are shortcomings to this product, such as:
They are not cheap
Not every brand works (I tried Samosite, they don’t work as well as the one I got from drug store)
They are not too durable – mine lasted 6 months
Your clothes get wrinkled – I need to iron my uniform at the hotel
However, if you have trouble fitting all your belongings in your suitcase, this product is worth a try.