A. O. Smith AO-MF Direct Connect Faucet Filter review
By Daryna Klochko · Published · Specs checked Oct 15, 2026 · 
Scores 10/10, tied for 1st of the 32 under-sink filters we track. At $79.99 it costs less than half the category median of $199.50. IAPMO lists it for Chlorine, Lead, Cysts, Microplastics, one of 29 under-sink filters out of 32 with a certifier listing for a health claim. Buyers on Amazon rate it 4.5/5 across 72 ratings.
A lower budget: $79.99, in the cheapest quarter of the 32 under-sink filters
- Price
- $79.99
- Certified for
- Lead · Cysts · Microplastics +3
- Flow
- 1.4 gpm
- Cartridge life
- 1,389 gal
- Cost per year
- $110
- Warranty
- 1 year limited
Certification
Listed by IAPMO under NSF/ANSI 42 · 53 · 401 for Chlorine, Lead, Cysts, Microplastics, checked Oct 15, 2026. Search the IAPMO listings
- Chlorine
- Lead
- Cysts
- Microplastics
The contaminants or other substances removed or reduced by this water treatment device are not necessarily in your water. Listing checked on Oct 15, 2026. What a listing means and what it doesn't
Specs and sources
Checked Oct 15, 2026 · source under each valueFiltration
Cartridges and install
Buying
Warranty, returns and shipping
30 days (Amazon).
Warranty: 1 year limited. Returns: 30 days (Amazon). Shipping: not stated by the brand. Source: A. O. Smith data sheet, checked Oct 15, 2026.
Source: A. O. Smith data sheet, checked Oct 15, 2026.
Compared with similar under-sink filters
All 32 under-sink filters →| Model | Price | Certified for | Cost per year | Warranty | Score | Where to buy |
|---|---|---|---|---|---|---|
| Frizzlife MK99 Under Sink Water Filter | $69.99 | Lead · Cysts +1 | $80 | 1 year | 10/10 | Check price → |
| 3M Aqua-Pure Filtrete Maximum Under Sink System (3US-MAX-S01) | $73.25 | Lead · Cysts +7 | $140 | 1 year | 10/10 | See specs → |
| Waterdrop 15UA Under Sink Filter | $76.99 | Chlorine | $18 | 1 year | 9.5/10 | Check price → |
| A. O. Smith AO-MF Direct Connect Faucet FilterTHIS MODEL | $79.99 | Lead · Cysts +4 | $110 | 1 year limited | 10/10 | Check price → |
| Express Water StreamLine Direct Connect USC001 | $85.99 | Lead · Cysts +6 | $98 | 1 year | 9.75/10 | Check price → |
What owners say
Checked Oct 15, 20264.5/5 from 72 ratings on Amazon. In our score this is 2 of 2 points. How we score
- Easy to install7 mentions7 positive0 negative
- Quality7 mentions7 positive0 negative
- Taste6 mentions6 positive0 negative
- Replacement5 mentions3 positive2 negative
Store ratings change over time; the date shows when we checked.