Product is a large, padded black vinyl envelope with a snap-down closure flap.
Very nicely done. The envelope is deep enough and wide enough to accomodate the hard plastic rails in the boot lip. With a little practice, I was able to work out a folding pattern that makes the boot lie flat within the dimensions of the storage bag. The bag and boot lies flat in the little well in the trunk if I fold a corner of the bag under to match the notched corner of the well.
A nice product for people who are compulsively neat and organized. If it sounds like a good idea and worth the $20, you probably won't be disappointed.