How long does one fill last?

Up to seven hours on a continuous setting with the 570 ml tank. Most people get a full evening or workday from one fill.

Does it need distilled water?

No. NOW says tap water plus a few drops of essential oil is enough.

Does it shut off on its own?

Yes. It cuts off automatically when the water level gets too low.

How much area does it cover?

NOW's copy cites up to 1,000 square feet, but real-world scent throw is best in a single room. Treat the figure as an upper bound.

Is it safe to leave running overnight?

It uses cool ultrasonic mist with no heat and has auto shutoff, so overnight use is common. Keep it on a stable surface away from fabrics.

The best new price was $32.40 at eBay as of November 8, 2026, the low end of its recent range. Check the price history before buying.

Where is the NOW Ultrasonic Steel Diffuser cheapest?

At eBay, for $32.40, 32% under what the other stores charge, as of our latest check.

What do buyers say about the NOW Ultrasonic Steel Diffuser?

Rated 4.7 out of 5 from 13 ratings.

Where can I buy the NOW Ultrasonic Steel Diffuser?

4 stores we checked sell it, including Herbspro, Swanson, eBay, Walmart.

NOW Ultrasonic Steel Diffuser

Best price now

$32.40at eBayObserved Nov 8, 2026, 3:01 PM

32% under what the other stores charge

Compared across 4 stores. Prices are checked against each store and labelled with when. Store links may earn us a commission.

Visit eBay

What reviewers say

4.7 / 513 ratings

Buyers rate it 4.7 out of 5 across 13 ratings, and the pattern is a diffuser that looks and runs better than its price suggests. Complaints are minor and mostly about upkeep and the cord.

What people mention

DesignPraisedOwners like the laser-cut metal look and say it stands out from plastic diffusers.
NoisePraisedReviewers describe it as quiet enough to run at a desk or bedside.
Run timePraisedThe long mist time per fill is one of the most mentioned positives.
CleaningMixedEasy to fill and empty, but the metal surface needs wiping to stay spotless.
Power cordCriticisedIt must stay plugged in, which limits where it can go.

About the NOW Ultrasonic Steel Diffuser

6 Hours Run Time Color Rotating Up To 1,000 Sq. Ft. NOW® Solutions Metal Touch Oil Diffuser unites scientific innovation with the timeless tradition of aromatherapy to create a BPA-free diffuser that uses only tap water and your favorite essential oils. Instead of heat, this contemporary diffuser utilizes high frequency ultrasonic electrical vibrations to create an ultra-fine mist, which helps to maintain essential oil integrity and holistic properties. With an automatic shut-off and up to six hours of whisper-quiet operation, this attractive diffuser complements your healthy lifestyle and is ideal for home and office. Aromatherapy and essential oils have been used throughout the ages as one of the oldest, non-invasive health practices. Scents have an effect on our mind and body, evoking memories, stimulating feelings, and arousing the senses. Certain essential oils then have the ability to relax, inspire, or create balance between the body and mind. At NOW® Solutions, we take the quality and purity of our essential oils very seriously. We go to great lengths to ensure that every oil we produce is brought to you in a manner that's both scientifically and environmentally responsible. Features Laser Metal Cut Design with Plastic Base Touch Sensor Technology Extremely Quiet Easy to Clean Just Add Tap Water and Essential Oils Cool Steam No Heat Involved/No Risk of Burns Runs Up To 6 Hours Automatically Shuts Off BPA-Free Great for Home or Office 1 Year Warranty Run Life 5000+ Hours Rotating LED Lights Specifications Model: 7486 Color: Black cover & base Misting Modes: Continuous/Off Light Modes: Color Rotating/Off Run Time: Up to 6 hours Water Capacity: 170 ml./5.75 fl. oz Coverage: Up to 1,000 sq. ft. Power: 100-240V AC Dimensions: 4.5" l x 4.5"w x 7.5"h