(Based on 2 reviews)
This is an unusual but effective gag, it is mouth-filling and renders the wearer completely unable to speak, even more so than a ball gag. It is thoughtfully made of decent leather with a discreet breathing hole. The rubber insert has a bit of a funny taste but this is worth it for its effectiveness. The only thing I would change would be for the front panel to be wider, to ensure the gag completely covers the mouth and the wearer can't get their lips or teeth over it.
I like the idea of the gum shield and it felt good when in the mouth. I did find I could move my mouth with it on. It would be good as a complete head harness.