Guardian Ultrasonic
Prevents your phone from secretly recording your private conversations.
Hear Guardian in action
See how Guardian Ultrasonic blocks phone recordings in a real-world side-by-side test.
Watch the introduction
A short overview of how Guardian Ultrasonic protects conversations at the table.
How it works.
Place your phone on Guardian to stop it from recording your voice.
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Place your phone
Set your phone on Guardian.
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Auto-detect
Detects your phone and turns on.
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Enjoy your privacy
Your conversations stay private.
trusted by companies worldwide
Protecting customers in 32+ countries
Private. Offline. Portable.
Built for privacy and performance, it runs without internet, Wi‑Fi, or Bluetooth, with a battery that lasts through long meetings and hardware designed in-house for maximum security.
Microphone Disabled
When placed on Guardian Ultrasonic, your phone can no longer record. You can talk freely without your phone secretly listening to you.
Battery Powered
The built-in battery will comfortably take you through multiple long lasting meetings a day, with over 4h of usage and over 1 week of standby time.
Offline
The Guardian device has no internet access, software updates, bluetooth, WiFi or any other gimmicks. Eliminating all attack surfaces.
Made in Austria
Designed and engineered by our team in Austria, from the circuit board to the firmware, with trusted components and software we control.
Stay fully reachable. Guardian only blocks the microphone — you never miss a call or message.
Customers in over 32 countries
Wherever the conversation matters, Guardian is on the table.
Built for trust
We put a lot of thought into what Guardian does, and what it doesn't. Learn how Guardian works and our approach to privacy.
Coincidence
Ever talked about something once near your phone, and then somehow it shows up as an ad?
Made in Europe
Hardware and software are fully designed by us in Austria.
Every component is designed and engineered by our team in Austria — from the circuit board to the firmware.
No outsourced modules, no third-party software. Full control over every layer means no hidden backdoors and no compromises on quality.
Technical SpecsFAQ
Is Guardian Ultrasonic a jammer? + −
No, not in the traditional sense. It doesn't block radio signals like mobile data, Wi-Fi, or Bluetooth. Guardian Ultrasonic uses ultrasonic acoustic waves (high-frequency sound) to physically interfere with microphones.
Does it block all microphones in the room? + −
Guardian Ultrasonic is designed to protect you from your devices recording your private conversations. It does not cover the whole room. (Be careful with products claiming to do so — they are usually misleading.)
Does it work with phone cases? + −
Yes, it works with most phone cases. Certain phone cases with a subpar build quality can sometimes block the microphone slightly. In those situations simply place the phone on the device without a case.
How should I transport the device? + −
Flip the power switch on the bottom to off. Use the original product packaging or a padded bag — the product packaging was specifically designed to protect the device during transport and includes space for the USB-C charging cable.
How do I store the device? + −
Flip the power switch on the bottom to off. You can still charge the battery while it's off. Store it in a dry place, away from heat or direct sunlight.
Is Guardian Ultrasonic safe for my phone? + −
Yes, it is safe. It doesn't affect your phone in any harmful way. The ultrasonic waves target microphones only and the device has been in use in our offices for a long time without issues.
Order with confidence.
- Fast shipping
- Ship out within 2-5 business days
- Free 14-day return
- No reason needed. Free return shipping & full refund.
- One-year warranty
- Warranty period subject to local laws
Guardian Ultrasonic