Scale Inhibitor, Prevent Scale Build Up On Hot Water Heaters. Waterdrop Ap431 Product Features ?Efficient Scale Inhibition?Food-grade polyphosphates, included in the Waterdrop scale inhibitor, can fundamentally inhibit scale formation to provide healthy water for you. This is a highlight different from conventional filters. ?Energy Conservation?This scale inhibitor can protect your water heater, dishwasher, boilers, downstream plumbing fixtures like faucets and shower heads from scale buildup while improving the efficiency of electrical appliances, and extending their life. ?High Flow Rate?3/4 " NPT inlet/outlet ensures high flow rate of 10 GPM to keep stable water pressure. This scale inhibitor system can be installed on any pipeline adaptive to its interface. ?Premium Material?This scale inhibitor system is equipped with a durable and anti-rusting 304 stainless steel adapter. Besides, its food-grade and BPA-free materials safeguard healthy water. Please note - this system is NOT a regular pre-filter. So it doesn't force all the water through the filter like a normal filter. Only a portion of the source water will flow through the filter to absorb food-grade polyphosphates for better filtration. ?Longer Lifespan?Enjoy purified water with this inline scale inhibition system. Every water cartridge can last for 6 months for regular use, which may vary based on local water quality. Please maintain this scale inhibitor system in an upright position during installation to get better inhibition effect. Be sure to install this system on a cold water supply line that supplies water to a water heater. Please NOTE, Waterdrop is an independent brand. The model name of this product is WD-W65, which is Replacement Cartridge for 3M Aqua Pure AP431, AP430SS. Shipping: Shipping is complimentary within the lower 48 US States. We Do Not Ship to PO/APO Boxes, HI or Alaska We Do Not Ship Outside of the Continental US All items ship within 24-72 hours of Payment For large items that require Freight shipping a valid phone number is required to call and schedule your delivery Terms of Sale and Feedback: Feedback is extremely important to us and If you are satisfied with our transaction, please take a moment to leave Positive Feedback. YOUR Satisfaction is our #1 Priority! If there are any issues, PLEASE contact us BEFORE leaving a neutral or negative rating so that we may resolve any concerns. We PROMISE we can make you happy if you give us a fair chance. Returns / Concerns: All items qualify for returns within 14 - 30 days of receipt. Buyer is responsible for return shipping on any item that is not damaged Please be sure this is an item you want before making your purchase. Customer Satisfaction is our TOP priority! All items are IN STOCK at time of listing. Inventory changes constantly and it is impossible to maintain a perfectly accurate count of all items. Please do not penalize us if we have to issue you a refund! Thank You For Your Business!