text: I have flat feet and developed planter fasciitis, it works very well and unlike other reviewers, it does not slip around for me may be cz I'm flat footed? I dont take them off to reuse them in other shoes but I will buy more to put in my other flats n heels. I didnt give 5 stars cz I wish they were a little higher, just half an inch or quarter inch higher would be great.