The Tommee Tippee Closer to Nature Perfect Prep Machine Replacement Filter filters every drop of water, removing any impurities and ensuring baby consumes the very cleanest water. Filter is designed for use with the Tommee Tippee Closer To Nature Perfect Prep Machine, providing the extra peace of mind that comes with knowing Baby's bottle will be perfect every time. These Perfect Prep Replacement Filters have a 150 litre capacity that remove impurities in your water for up to 3 months (based on consumer preparing 6 x 260ml bottles per day). A warning light on your machine will indicate when your filter is coming to the end of its life. This same light will then flash when the filter needs immediate replacement, giving you the peace of mind that your machine is working safely for you and your baby. Breast milk is best for your new baby, but if you are making the move to formula milk, Perfect Prep is everything. Features & Benefits: - Filters every drop of water before mixing with formula powder. - Removes impurities resulting in the very cleanest water for Baby's formula. - Each filter lasts up to 3 months*. - Only for use with Closer to Nature® Perfect Prep machine. - Always BPA and phthalate free.