Hi, DAF and the Edinburgh Masker are stuttering prosthetics much the same as eyeglasses and hearing aids are vision and hearing prosthetics. Since stuttering is a neurological disorder relating to speech processing the prosthetic modifies the disorder and the person who stutters is able to speak much better. I wear the Edinburgh Masker most of the time just as I wear my eyeglasses most of the time. My sons use DAF at school but not while playing sports. It has brought about positive changes to the entire family. If you have further questions you can use Google for more information. I would also be happy to help. Obviously there are some bullies here with their own negative opinions. I have asked the administrators to stop the bullying, but they have ignored my request. Very sad that such ill mannered people are allowed to interfere. We need positive information not ill informed displays of nonsense.