Frequently asked questions
Is ultrasonic cleaning safe for coated lenses?+
Yes – the NURO system was built exactly for this. Cleaning is contact-free, so no micro-scratches occur. Mirrored and polarized sports lenses handle the cleaning without issue too. Our fluids (Klarberg × NURO Concentrate and NURO Premium Fluid) are pH-neutral and tuned for premium coatings. Exception: lenses with damaged coatings or antique mirror finishes – when in doubt, ask our support.
How do you dose the Klarberg × NURO Concentrate?+
One teaspoon (approx. 5 ml) of concentrate per tank fill – that matches the 1:20 mixing ratio with water. The exact dosage is also printed on the included product insert.
Why does wiping sports eyewear with a jersey or cloth damage the coating?+
Dry wiping drags embedded sweat-salt, dust and sand particles across the lens surface like fine sandpaper. Over time this creates micro-scratches that attack anti-reflective or hydrophobic coatings. Ultrasonic cleaning lifts these particles contact-free via cavitation – with zero friction on the lens.
Do I need a cleaning fluid at all?+
No. NURO cleans very well with plain water – 48,000 vibrations per second do the work. Our fluids speed things up with sweat salts, grease and styling residue, and additionally care for coatings.
How often should I clean my glasses in the ultrasonic bath?+
Sports eyewear: ideally after every sweaty session – sweat salts are the most common cause of corroded hinges. Everyday glasses: once or twice a week is plenty.
What is the difference between the Concentrate and the Premium Fluid?+
The Klarberg × NURO Concentrate is the pro formula: highly concentrated (1:20), up to 400 cycles per litre, ideal for intensive studio use. The NURO Premium Fluid is our gentler in-house formula for daily use at home – fragrance-free and biodegradable.
Can I clean jewellery and watches too?+
Jewellery: yes, except soft stones (pearls, opals, amber) and glued settings. Watches: only waterproof models, or straps separately – the included watch holder keeps the case above the bath.
How loud is the device?+
Under 45 dB – quieter than a fridge. The NURO hum is practically unnoticeable in a salon or hotel.
Is a power adapter included?+
No. Included is a USB-A-to-USB-C charging cable (the USB-C end connects to the device). You'll need either a standard USB-A power adapter, or you can skip the included cable and use your own USB-C cable with a USB-C power source instead.
How should I place my glasses in the tank?+
Always resting on the frame or temples, never lens-side down. If the lenses rest directly on the tank floor, the cavitation vibration can knock them against the stainless steel and cause scratches.
Do you offer invoice payment for businesses?+
Yes. Business customers (studios, salons, hotels, bike cafés, opticians) simply send a B2B inquiry via the contact form – we reply within one business day with a tailored offer including invoice payment.
Is this scientifically backed?+
Yes. A study by Furtwangen University (Fritz et al., Scientific Reports 2020) found over 5,232 bacterial species on worn spectacles. An earlier study by the same research group (PLOS ONE 2018) showed: wet cleaning removes 99–100% of germs, while dry wiping with a cloth removes only 85–90%.
What is your return policy?+
All our products can be returned within 14 days. Return shipping is at your own cost. Please note: once the ultrasonic cleaner has been put into use with water, a return is usually no longer possible for hygiene reasons.
Do you ship outside Germany?+
Currently we ship with Hermes (€5.79, free from €100) within Germany. More countries (including Austria) are coming – register via the contact form and we'll let you know at launch.