Its use:
The roller is large enough to massage the 2 legs together.
It is quite valid to make free automassages or as described in the CTS method Christophe Carrio or his book A body without pain.
The price:
Lower than the rollers of the best known brands (blue to orange pip or "grid" for example.!)
allowing you to buy a roll and a book or a roll and a massage stick same brand for the same price ...