Which Dyson models does this battery fit?

It fits V7 Motorhead, V7 Fluffy, V7 Animal Pro, V7 Trigger, V7 Car+Boat and SV11. It does not fit V6, V8, V10, V11, V15, SV10 or SV12, or any screw-in model.

Is 8000mAh more runtime than the original?

The rating is higher than the stock V7 pack, but real runtime depends on the cells used and the power mode. Expect longer cleaning per charge, not a guaranteed multiple of the original.

How does it attach to the vacuum?

It uses pressure terminals and slots into the V7 battery bay. It is not a screw-in pack, so check your model before ordering.

Will it work with the original Dyson charger?

It is a 21.6V lithium-ion pack built for the V7, so the standard V7 charger is what it is designed for. Charging time will be longer than with the smaller stock pack.

Is a third-party battery worth it over a Dyson one?

It keeps a working V7 running for less than a new vacuum. The trade-off is that third-party cells can lose capacity faster and carry no Dyson warranty.