The Next Era
 of Protective Masks

See what sets us apart from other masks.

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About the Filter

Our G-Series Masks use a 4-ply filter composed of 4 layers of filtration materials. The mask has no valves. Air is filtered in both directions, inhale and exhale. When in use, the filter's blue side (PP Meltblown) should be facing in towards you.

The G-Series filter has been lab tested by several third-party labs. Results from these tests have shown a level of filtration efficiency score considerably higher than 95% across multiple lab tests.

NELSON LABS (8.13.20)

Passed NaCl Test

Average across 20 tests

Filtration Efficiency

98% Filtration

Must be 95% or greater for NIOSH

Particle Penetration

< 2% Penetration

Must be less than 5% for NIOSH


About the Mask

The CastleGrade G-Series Masks use a patent-pending design made from a soft, form-fitting silicone base. The natural self-suction offers a seal superior to surgical or cloth masks, while providing more comfort than N95 masks.


Sensitivity Test

Passed | Required for FDA 510k


Irritation Test

Passed | Required for FDA 510k



Passed | Required for FDA 510k

Reusable & Sustainable

Looking Forward For Solutions

Single-use plastics and protective gear is a problem. We strive to have our products truly embody a mindset of sustainability.

Our G-Series masks are reusable, thereby decreasing overall waste and minimizing the impact on our environment.

Food-grade silicone

Food-grade polycarbonate

4-Ply filter

Food-grade polycarbonate

Food-grade silicone


The Stone Bag

Our G-Series Masks and Replaceable Filters come safely sealed and packaged in the CastleGrade™ “Stone Bag”. 
The packaging will completely biodegrade in 14 months and does not need to be recycled.

Safety & Comfort

What Sets Us Apart

The G-Series Masks offer a best-in-class level of protection, while providing a comfortable, reusable product that you can wear everyday.

Provisonal Patent on Reusable Silicone Mask

We have patent pending with the USPTO

Efficiently protects against microparticles

Tested to block over 95% efficiency

Soft, form-fitting design with high breathability

The silicone base allows for all-day comfort

Eco-friendly materials, reusable design

Reuse the mask daily, just change filters

Easily cleaned by
 wiping with disinfectant

Sterilized with boiling water or 75% alcohol

Mask fits with glasses comfortably, no fog

Wear without having your glasses fog up