Its useful when you need to undo a screw but access is restricted so you can't use a traditional screwdriver. For the price its worth having in your tool box, it may get you out of a spot and save a lot of time and money, though if I needed it regularly I would upgrade to something better.
Had a similar one to this that I used for a while, helped me out a few times,robust enough for price, I'm a heating engineer. Upgraded to Bahco 2058S26 now though
Offset Ratchet Screwdrivers. So hot right now.
Thanks nice find
Same item same seller £3.15 on eBay with free p&p for those who don't have prime. Item no.392326177386