Rank #7 in Best Water Flosser 2026: 10 Ranked, and Why the Cheapest Wins
AUIEI Y209 Water Flosser, 300ml, 5 Modes, USB-C
Price and rating as shown on Amazon when we collected them. Both change.
The AUIEI Y209 is a cordless water flosser with a stated 300ml tank, five cleaning modes, four nozzles and a USB-C rechargeable battery. At £19.99 it is the cheapest model in this guide, and it takes the number 7 slot on the strength of one comparison: it carries 6,399 ratings at 4.3, while the £69.99 Waterpik Cordless Advanced carries 6,194 at 4.2. Almost the same number of buyers, roughly a third of the money, and the cheaper listing is the one that actually publishes a tank volume.
The listing is not tidy, though. It describes a 300ml tank and a 1,500mAh battery charged over USB-C in 4-6 hours, but the specification table underneath also says "3 A batteries required. (included)", which cannot both be true of the same device. The description claims "about 21 days of continuous use" from that 1,500mAh cell and never gives a minutes-per-charge figure to check it against. Everything on this page comes from the Amazon listing for the AUIEI Y209 — the prices, ratings, modes and claims are the seller's, not the result of any testing we have done.
How those 6,399 ratings break down
An average hides its own shape. This is the spread behind the 4.3 stars.
Specification
Exactly as published on the Amazon listing, field for field.
| Price | £19.99 |
|---|---|
| Amazon rating | 4.3 out of 5, from 6,399 ratings |
| Tank volume | 300 millilitres |
| Pulse frequency and pressure | 1,400-1,800 pulses per minute at 30-110 PSI (as listed) |
| Modes | 5 (Strong, Normal, Soft, Pulse, Child) with memory function |
| Waterproofing | IPX7 |
| Battery | 1,500mAh, USB-C, 4-6 hours to charge, "about 21 days of continuous use" (as listed) |
| Batteries field | 3 A batteries required, included — the same listing describes a built-in USB-C battery (as listed) |
| Size and weight | 25 x 8 x 7 cm; 380 g |
| Bestsellers rank | 38th in Power Flossers & Irrigators |
What buyers actually say
Quoted from customer reviews on Amazon
Verified purchase“This is so much better than my previous one. It has a strong setting that works really well, once you work your way up to it.The reservoir is big enough that you can clean your whole mouth without refilling. The water uptake tube is flexible with a little ball on the end that makes sure that it doesn't matter which way you are holding the flosser. It is easy to fill either from the top or through the opening on the side.Some hints for when using: The jet is powerful, so make sure you keep your mouth very firmly shut during use. Use warm water as cold can be painful. As previously stated you need to work your way up the settings, sticking on one if there is any bleeding.”
Verified purchase“It does everything I need, easy to use and the charge lasts a long time”
What it is up against
The rivals it was ranked against in Best Water Flosser 2026: 10 Ranked, and Why the Cheapest Wins.
Questions people ask
How big is the water tank on the AUIEI Y209?
The listing states 300ml, in a detachable tank that can be filled either through the large top opening or by removing it.
How many pressure settings does the AUIEI Y209 have?
Five: Strong, Normal, Soft, Pulse and Child. The listing says it remembers the mode you used last, and runs at 1,400-1,800 pulses per minute at 30-110 PSI.
Is the AUIEI Y209 waterproof?
The listing gives it an IPX7 rating and describes the tank as detachable for regular cleaning to avoid water residue.
How long does the AUIEI Y209 take to charge?
The listing says 4-6 hours for the 1,500mAh battery, which it claims gives "about 21 days of continuous use". It does not say how many minutes of flossing that works out to per charge.
Does the AUIEI Y209 take disposable batteries?
The specification table says "3 A batteries required. (included)", while the description says the flosser has a 1,500mAh battery charged by USB-C. Both statements appear on the same listing.
How loud is the AUIEI Y209?
The listing claims the pump runs at less than 55db; no independent measurement is given.
Comments
Reader comments are not checked against the manufacturer's claims above.
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