[iso1210]

Use ddg in the UK, type "buy n95 mask", 3rd result down is

https://www.buyfacemasks.co.uk/

No idea how reliable they are, but that's always the danger when you buy anything from a small shop. I don't like the look of is as I can't find any corporate information about the store on their site, but it's no worse than buying anything else online.