It’s for an LR drone. What people use for pushing the range limits on a quad. The 25mW Walksnail challenge for example.

Well, kinda. They’d make their own from bulk cells, but you get the idea 💛

Calling bullshit on that battery info RE: FPV drones matey.

That’s a 4000mAh 4s Li-Ion pack. No racers use Lithium Ion, and definitely not 4AH.

That’s a long range FPV pack, and it’ll go for about half an hour to an hour on an appropriate LR quad.

A typical racing machine will run on 6s 1300-1500mAh Li-Po packs which are significantly lighter and smaller than your provided link, as well as higher voltage.