Thanks TopTrump. Great find and ordered
O2 branch had no stock (apparently due to throttling of stock from OnePlus) and was trying to get me to buy a Belkin unit claiming that it was more powerful (which was complete BS as he was quoting the sum of both ports' power output as available to one device - he was winging it). Same sales staff said he couldn't price match anyway. Lack of knowledge is what's killing the high street. O2 have got it on their site for full-extra price @ £29.99, but you might want to try calling them on 0344 809 0202 to see if they'll price match.
O2 sometimes run promotions on OnePlus's accessories 25% or thereabouts off. I presume you've got the 6T, as the 6's protector £14.36 @ OnePlus. https://www.oneplus.com/uk/store/cases-protection It is worth getting the genuine though to not ruin the user experience. Fit n finish is superior to the next best brand I found, Orzly which wasn't quite right (non-chamfered edges, non-matching screen bezel borders and a couple of air bubbles). Maybe they've improved for the 6T?
That's good enough for me Waiting for the glass screen protector to come down in price it's £18 + pounds 😳
Site's product description "In the Box: 1 x OnePlus Fast Charge Car Charger 1 x OnePlus Fast Charge Type-C Cable" Not sure of the cable's length though.