Most "EMP bags" block your iPhone signal. And nothing else.

Quality bags do — junk bags don't. The standard is MIL-STD-188-125, the U.S. Department of Defense specification for HEMP (high-altitude electromagnetic pulse) protection of mission-critical equipment. The attenuation requirement: 80 dB across 14 kHz to 1 GHz. Bags meeting that specification protect against the relevant EMP waveforms (E1 fast pulse, E2 lightning-like, E3 slow geomagnetic). Bags rated only for cellular-signal blocking (~30–50 dB at GSM frequencies) protect against your phone, not against EMP. Read the spec sheet, not the marketing.

Same physics, different specifications. A Faraday bag is the general category — passive shielding via metallic enclosure. An "EMP bag" is a Faraday bag specified to attenuation levels and frequency ranges that match documented EMP threat waveforms. The relevant standards: MIL-STD-188-125 (DoD HEMP), IEEE 299 (general shielding effectiveness measurement). 80 dB across 14 kHz – 1 GHz is the working floor for genuine EMP protection. Most "EMP bags" on Amazon under $40 do not approach this — they're cellular-blocking pouches with EMP marketing.

80 dB minimum across the EMP-relevant frequency band (14 kHz – 1 GHz) per MIL-STD-188-125. The REVIS-1 Executive Guard tests at 76–85 dB across 30 MHz – 10 GHz — covering the high-frequency EMP and modern wireless threat band, with margin. For very-low-frequency E3 protection (geomagnetic-storm-like, < 1 kHz), additional considerations apply: most consumer Faraday bags do not address E3, and grid-scale E3 protection is a different engineering category. For protecting devices from E1 (fast pulse, the dominant threat to small electronics), 80 dB across the high-frequency band is what matters.

The devices that would be hardest to replace and most useful in a post-event scenario: a backup smartphone (loaded with offline maps, contacts, reference documents), a portable HF/VHF radio, a hand-crank or solar charger, a backup laptop or tablet with critical documents, hard-drive backups of essential records, and any specialized medical electronics. Keys, spare batteries, and currency don't need EMP protection — they don't have semiconductor components.

Partially. You can verify cellular and WiFi blocking by sealing your phone in the bag and trying to call it, ping it, or AirDrop to it — if any signal gets through, the bag fails the basic test. You cannot test EMP attenuation without IEEE 299 lab equipment (anechoic chamber, calibrated antennas, network analyzer). For consumer-grade verification, the cellular/WiFi test plus a published spec sheet from the manufacturer (showing IEEE 299 or MIL-STD-188-125 test results from an independent lab) is what matters. See our DIY test protocol for the full procedure.

The REVIS-1 Executive Guard meets the relevant requirements: 76–85 dB attenuation across 30 MHz – 10 GHz (covering the high-frequency EMP and modern wireless threat band), three independent shielded chambers (laptop, tablet+phone, wallet+keys+RFID), boardroom-appropriate exterior so the bag works for daily executive carry AND emergency-prep purposes, and U.S. manufacturing for procurement-compliance. Spec-sheet documentation available on request. $129. Made in the United States.