Jewellers loop size?

what magnification strength should I be buying? I'm looking at a x50 will this do or is there a desired one?

Thanks fellow cultivators.

That's fine...I think some are 30x

my fav is from radio shack a 60-100x zoom i mean perfect for trichome viewing

and 12 dollars for that pocket magnifier

Uk jobby for me pal.
Not much eBay doesn't have.