These Mouthspreaders can be used as gags, aided by the neck strap, compared with other retractors, which can be spit out by the wearer. This hightens the kick, but requires extra watchfulness.
Please keep an eye on the person wearing it and remove immediately as soon as they start gagging. This risk is present, as swallowing is made difficult with the mouth forced open.
The required size depends on the width of the head, as only the small dent in the middle grips between the front teeth. With help of the locking grid the mouth can then be spread open in different positions.