What you're actually getting
For roughly fifteen quid, you get a 20,000mAh brick that charges at up to 45W, has a digital percentage display on the front, and - here's the bit people actually care about - a built-in cable. No more rooting around your bag at Euston station wondering where you left your USB-C lead. That alone is worth something.
The display is a nice touch. Not a vague four-dot LED strip, but an actual number. Knowing you've got 37% left is more useful than guessing which dot means "nearly dead".
Who this is for
Honestly, this is for the person who travels light and hates faff. One object, no loose cables, decent capacity. If you're away for a long weekend and want to keep your phone and maybe a tablet alive, this does it without making your bag heavier than it needs to be.
It's not really for the tech obsessive who wants to charge a laptop properly - 45W passthrough is solid but not going to fully satisfy a MacBook on a long haul. And the integrated cable, while clever, does mean if it breaks you can't just swap it out.
One small reservation
The brand isn't a household name, and there's no listed "was" price here so the discount framing at checkout is worth treating with a bit of scepticism. That said, INIU has generally held up fine in community reviews, and 917 degrees of heat on HotUKDeals suggests real people are buying it, not bots.
At this price, the risk is low. Personally I'd chance it.