Something to remember with both External & Personal drives is that if you have access or use both Mac & PC ...
Format/ plug in to a PC
first so when you later plug into a Mac, a small file will be added and you can swap and see
plus share those files easily!
When Mac formats the FAT32 device it will take it over and without mucking around, will only see Mac in Mac & PC
on PC = weird! Defo ... a hassle but that is heaps easier then setting up the different permissions, that you need to make,
if you have it "appleafied" from the get go