As a device, I had a DAF device made by an engineer from Moscow. I bought it for a slightly cheaper price. He said you will experience delays in applications and not get the full effect. He said the delay should be in milliseconds, not seconds. Like 0.1ms. I wore it a few times and it started bleeding, but then I tried some methods and it wasn't necessary anymore. The device remains in the drawer, you never know what will happen in the future. It looks like a Bluetooth headset, but the electronic circuit inside has been changed, that is, it is specially made.