That will be a plus battery. Heavier than the standard battery and not available from DJI in the UK. Takes the drone over 250g and maybe causes it to broadcast RID info.
You can take your chances with used batteries on eBay but I prefer the genuine refurbs sold by DJI.
Here in the US, we have an electronics store called Best Buy and they sell open box at a discount and for DJI batteries, they have often never been used (not activated). I cleaned them out of their open box NEO batteries.
By the way in case anyone is interested, due to their being a major supplier of drone batteries, Ali Express is now officially defunct and out of business. I bought numerous extra-range batteries for my Mavic 1 Pro, Mavic 2 Pro and Air 1, prior to Ali Express' sudden collapse, so it is sad to see that company vanish suddenly like that.
Apologies for the minor digression, but in the past, when it came to shopping for after-market DJI drone batteries, Ali Express would have been my first suggestion. So while I cannot recommend a supplier of batteries to the OP with Ali Express having gone belly up, I can at least mention where NOT to place an order.
