Do not purchase unless link was sent directly from CastleGrade Team.

T10 Testers

Regular price $44.99
Unit price  per 
Shipping calculated at checkout.
This product is now shipping!

Tested by

All sales are final.


Do not purchase unless link was sent directly from CastleGrade Team.


Provisional Patent

U.S. Patent & Trademark Office
  • CastleGrade makes superior masks that actually allow you to breathe comfortably and if you wear glasses they do not “fog up”.

    Martha Stewart

Frequently asked questions

Entrepreneur and business owner Anna Grinvald invented an earlier version of the G-Series in December. Anna’s mother lives in a senior care center in Israel and complained about how typical masks were fogging up her glasses. Ron Grinvald, a former injection mold specialist for several parts on the NASA spacesuit worked with Anna and eventually Dan Castle, owner of Castle Brand Group to improve it. The G-Series filter has recently been tested by Nelson Labs, Alpha Labs and SMQ Labs and has performed extraordinarily well.

The G-Series filter has been tested by several third-party labs. Results from these tests have shown a level of filtration efficiency over 95% consistently, with Nelson Labs performing the Bacterial Filtration Efficiency (BFE) test which returned a 99.8% efficiency score.

Please click on the Science tab to learn more.

As a standard, we recommend purchasing the G9 size. The G8 size is recommended for teenagers and women with small head and face features (70pct of women prefer G9).

Remove the 4-ply filter and place it in the dishwasher. You can also submerge it in boiling water for 2 seconds. If you prefer to keep it clean throughout the day you can wipe it down with any disinfectant.

You can wear the mask for up to 1 week or 32 hours of direct use, before replacing the filter.

Wearing a high protective, silicone mask will slightly alter / muffle the sound of your voice.

We manufacture in several countries including Vietnam, Czech Republic, Germany and China.

Don’t! Keep the mask and buy replacement filters on our website when you are running low or sign up for the subscription so you never run out. We cringe seeing so many masks being discarded after just one day of usage and Mother Nature needs your help.

For safety purposes, once the product has shipped, we consider the mask unfit for use by another customer. Thank you for understanding.