The Perfect Prep was one of my absolute best baby buys, so these filters are crucial. My first filter lasted 4-5 months (making 4-6oz bottles), and the second one has just been changed after 3 months now that we are making much bigger bottles so they do last for ages. The only negative point I would say is that the instructions that come on the filter don't match the full instructions that come with the machine and they don't tell you to press the filter reset button to make the light go off. This doesn't seem like a big problem, but I can't see that button on my machine because of where it is sat in my kitchen, and I was trying to change the filter in a rush as the next bottle was due and got completely flustered and had to google the full instructions.
Verified Purchase This review is from: Tommee Tippee Closer to Nature Perfect Prep Replacement Filter (Baby Product)