This Li-Ion replacement cell phone battery w/ Back Door is 100% compatible with the Motorola I733 NEXTEL FALCON SERIES. Our batteries and accessories are made with high quality parts and are guaranteed to meet or exceed the original equipment manufacturers specifications at a reduced price. All batteries are tested for 100% quality control assurance. This Motorola I733 NEXTEL FALCON SERIES replacement cell phone battery w/ Back Door includes a 1 year warranty to guarantee that it has no manufacturing defects.