THE SCIENCE BEHIND THE MASK
The Next Era of Protective Masks
See what sets us apart from other masks.
MAXIMUM PROTECTION
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

SUPERIOR SEAL
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.
Toxicon
Sensitivity Test
Passed | Required for FDA 510k
Toxicon
Irritation Test
Passed | Required for FDA 510k
TOXICON
Biocompatibility
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

BIODEGRADABLE PACKAGING
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