In my local Swimming pool in Watford, UK. They don't allow me to use this device. They told me the life guards are not trained to remove this devices from a person's mount in case they need to rescue someone and perform "kiss of life" to resuscitation technique. I find this an extreme example of Nanny State in the UK. Treating adults like kids in this manner is embarrassing and humiliating as well as patronizing. He went to argue in a patronizing way that the drills to learn butterfly don't require the use of this device. With such mindset I wouldn't even consider taking tuition with someone so narrow minded and overbearing. There is something very wrong with the "nanny state" in the UK. #NoNannyState
If someone knows a swimming pool in London where they allow the use of this device, please let me know.

this one its much better... Powerbreather just have a look there are videos on youtube