The Uowlbear Replacement Battery For iPhone 6 is will work perfectly with your iPhone 6 model. It has higher capacity of 2300mAh, higher than the original battery.
It is a 0 cycle battery and has never been used and seller is stating it should last over 700 charging cycles. Its tested under strict quality control and is equipt with Over-Charging, Over-Discharging, Over-Heating and Short-Circuiting Protection. It's also CE and RoHS certified.
The battery can be replaced easily, and comes with all the required tools to do so.