Skyfoot Carbon Fiber Insole | Trimmable Rigid Shoe Insert for Foot Support, Orthotic Shoes Stiffener Inserts with Energy Return & Explosiveness to Prevent Foot Sore and Fatigue | Small - Women's 6-10

If you need firm support after a fractured foot, or foot surgery, these are too flexible to be any good, and can cause further damage.

Edited... Ability to trim to fit is great. Cushion on top so it can be used on its own and in shoes without a removeable insole is great. Sadly, the 'rigid' part of the insole isn't very rigid and doesn't prevent bending at big toe joint as much as hoped. There is some resistance with fingers and does only curve vs bend to 90 deg corner.However... in slip on dance shoes, it has proven more useful than the more rigid inserts. Some resistance, but enough flexibility that foot stays in shoe, with the super rigid ones, shoe stays, heel comes out, toe bends, useless :-(. These have turned out to be much better than thought at first test and am now buying a 2nd pair but larger so less trimming zone left over.