Last updated: March 14, 2026
Frequency Blockers is an independent editorial site. We want to be completely upfront about how our product evaluations work.
How Our Reviews Actually Work
We do not purchase, test, or physically handle any products. We do not operate a testing lab. Our reviews are created using AI-assisted research and analysis. AI gathers, organizes, and summarizes information from publicly available sources — manufacturer specs, independent lab reports, verified buyer feedback, and domain research.
Our 6-Point AI Research Framework
Every product goes through these six evaluation checkpoints before earning a recommendation.
1. Attenuation Specs Analysis
AI examines the full frequency range of shielding claims, not just a single headline number. A bag claiming 80 dB at 1 GHz may only deliver 40 dB at 6 GHz — and that matters for modern devices.
| Attenuation (dB) | Signal Blocked | Real-World Meaning |
|---|---|---|
| 20 dB | 99% | Basic shielding, blocks most casual signals |
| 40 dB | 99.99% | Solid protection for phones and key fobs |
| 60 dB | 99.9999% | Professional-grade, meets most MIL-STD requirements |
| 80 dB | 99.999999% | Lab-grade isolation |
| 100+ dB | Virtually total | Government/military specification |
Special attention is paid to performance at higher frequencies (5 GHz+), because Wi-Fi 6E, 5G, and UWB car key systems all operate in those bands.
2. Aggregate Buyer Review Synthesis
AI analyzes buyer reviews across Amazon, manufacturer sites, and independent forums — looking for recurring patterns in praise, complaints, and how manufacturers respond to issues. Products generally need 50+ verified reviews before being considered well-vetted.
3. Material and Certification Research
AI researches shielding materials (copper, nickel, silver, conductive fabric blends) and verifies claimed certifications against standards like IEEE 299, MIL-STD-188-125, and ASTM D4935. Products backed by third-party lab reports score higher. When lab data isn’t available, that’s noted.
4. Use-Case Fit Assessment
A Faraday bag for car keys has different requirements than a laptop sleeve. AI evaluates each product against its intended use: key fob protection (LF, UHF, UWB bands), phone pouches (cellular, Wi-Fi, GPS, NFC), laptop sleeves (shielding + physical protection), and large enclosures (seal integrity).
5. Price-to-Value Ratio
Price is compared against shielding performance, build quality, features, and warranty terms to identify genuine value. Expensive doesn’t automatically mean better.
6. Brand Reputation and Support
Track record of each manufacturer: years in the EMF shielding space, transparency of test data, warranty claim handling, and accuracy of marketing claims.
What We’re Honest About
- No one has tested these products in a shielded chamber. Evaluations come from AI analysis of publicly available data, not hands-on testing.
- AI isn’t perfect. Specs can change, lab reports may not be current, and real-world performance varies with environment. If you spot an error, let us know.
- Independent lab tests are the gold standard. When a product has accredited third-party lab data, it carries more weight than manufacturer self-reported specs. AI references these reports directly when available.
- We use affiliate links. When you purchase through our links, we may earn a commission at no extra cost. This does not influence recommendations. See our Affiliate Disclosure.
Corrections and Updates
If you are a manufacturer with lab test data you’d like considered, or a reader with firsthand experience that contradicts a review, please contact us. Accuracy is the goal, and real-world feedback makes the content better.