About This

• Do It Right Once, Then Enjoy It with Ease – Installation and filter replacement take a bit more time and effort than twist‑on disposable 1-stage, but a worthy trade‑off for longer filter life, better filtration, and lower long‑term cost. Search YouTube for "How to Install iSpring US31KF Under Sink Water Filtration System" before purchasing. You‘ll find you can do it.
• Classic 3-Stage 2.5x10-inch Olddies: Invented in the 1970s and a de facto industrial standard and the most popular so far. Why? Repliable, Trustworthy, Get the job done, and, fortunately or unfortunately, Dirt Cheap, only $17.43 for 3 stages under counter water filter pack iSpring F3.
• True 3-Stage Design For Deep Chlorine Removal. Pure water can’t be rushed. While typical single-cylinder filters let water rush through a thin layer of media, the US31KF features a True 3-Stage system that triples the filtration path. This significantly extends the contact time with our premium carbon media, allowing it to thoroughly absorb chlorine—the main culprit behind bad taste and chemical odors. The result is a deep level of purification and bottle-quality freshness that rushed, single-stage alternatives simply cannot match
• You Pay for Filter, Not Disposable Plastic: The third‑stage carbon block filter delivers ~13 oz of activated carbon in a reusable housing built to last 5–10 years. That’s 2.3× more carbon than quick‑change twist‑on cartridges, with only ~1 oz of plastic. Those disposable cartridges pack just 5 oz of carbon inside a 12‑oz plastic shell – then get thrown away after one use. Every quick‑change cartridge you buy funds plastic waste, not clean water.
• What You See Is What's Caught – The transparent housing lets you see your filter color change and mud buildup in real time, so you know your money is at work — not on guess.
• Lifetime Local Support – Enjoy a 30-day money-back guarantee, a 1-year limited warranty, and lifetime technical support from our Atlanta, GA team – real people, real help, right here in the U.S.
• Don’t want to drill or modify your kitchen? Traditional under-sink filters require permanent countertop changes — US31KF connects directly to your existing cold water supply with standard 3/8″ compression fittings. No drilling. No extra faucet. No plumber.
• Healthy Minerals Retained (Does Not Lower TDS): Unlike RO systems, our chlorine removal under sink water filter reduces harmful contaminants while keeping beneficial minerals.

Overview

• Brand : iSpring
• Special Feature : Multi Stage Filtration, Portable, Heavy Duty, Leak-Proof
• Product Dimensions : 15"L x 9"W x 17"H
• Material : water filters
• Capacity : 10000 gallons
• Included Components : Direct Connect Hoses
• Package Information : Bottle
• Installation Type : Under Sink
• Purification Method : Reduce PFAS
• Item Weight : 12.3 pounds