Hlk-pm01 input fuse and required filtering?

[Hixfield]

I am using the http://www.hlktech.net/product_detail.php?ProId=54 PSU brick, it works very nicely and is cheap (approx 2-3 usd on aliexpress). See this nice review: https://www.eevblog.com/forum/projects/performance-test-and-review-of-mains-to-5v-0-6a-hi-link-hlk-pm01/

In v1 of my PCB I just connected it straight to the mains without any fuse or filtering.
Now I am designing the updated PCB and when reading the review I am wondering:
- should I add a fuse on the mains input for safety? Are there any (CE?) regularions that makes this mandatory?
- what kind of fuse? Resettable?
- should I add some filtering or something? Also to meet regulations?

I dont have much space, so any suggestions for small smd fuses/filtering would be appreciated.

[Hixfield]

Given the number of replies I guess its not such a intelligent question :-)
I did some further research and found this article:

https://skippy.org.uk/quick-look-at-the-hlk-pm01/

It contains a diagram with a fuse (800ma, http://be.farnell.com/bussmann-by-eaton/c310fc-800-r-tr1/fuse-pcb-0-8a-250vac-fast-act/dp/2464451) and a varistor (http://be.farnell.com/epcos/b72210s0271k101/varistor-43-0j-275vac/dp/1004390).

I decided to order from conrad so:

Fuse : http://www.conrad.be/ce/nl/product/537512/ESKA-883116-Printzekering-Radiaal-bedraad-Hoekig-800-mA-250-V-Traag-T-1-stuks/SHOP_AREA_17392

Varistor: http://www.conrad.be/ce/nl/product/500592/Schijfvaristor-S10K275-430-V-Epcos-S10K275-1-stuks/SHOP_AREA_17441

I feel confident about these choices but if somebody could provide a second opinion that would be nice.

[Sjoertdb]

Maybe this thread might give some good information as well: https://www.element14.com/community/thread/56397/l/ac-mains-on-a-pcb?displayFullThread=true

[Hixfield]

Thanks for the link, this confirms my proposal!

[beic]

I know it's a old topic, but I'm little bit confused about varistors.

B72210S0231K101 and B72210S0271K101 from EPCOS / TDK

are these interchangeable with the:

10D241K and 10D271K from BURNS

Thank you!