I have been using free issue NHS hearing aids for about ten year. In that time I have had two makes. German made Siemens and Swiss made Phonak. Both have been excellent in giving me adequate hearing with little or no difference between them. The big bonus came when for the first time in 25 years, I no longer had to suffer the din of tinitus. This applied to both makes. The Siemens aids could be controlled via my phone to alter volume and pitch. When new aids were deemed necessary, I was given the Phonak aids. As I have already explained, there was no noticeable difference. However, the Phonak aids do not allow me to adjust volume or pitch but they do have Blue Tooth which offers other advatages. Both devices fit behind the ear with lifelines which are replaced, free of charge every six months by the NHS. Batteries with the Siemens lasted about a week whilst with Phonak they last 1 -2 days. These are also supplied free upon request. I do not know if the free issue applies only to pensioners. Before I went through the NHS, I did try Boots but found they were a con and the audiolgist just a glorified salesman. The only sales talk with the NHS was - "take them or leave them". Absolutely no pressure. You may have to be recommended by your doctor to the NHS. I was after she learned my previous tests had been performed by specsavers. For those afflicted by tinitus, the makers Siemens and Phonak do not guarantee the success I have had but the technicians say it is a high %.