This Kajeet RC400L(X) 4G LTE mobile hotspot comes professionally refurbished and pre-installed with RayHunter, the open-source cellular surveillance detection tool trusted by researchers, privacy advocates, and security professionals. RayHunter continuously monitors LTE signaling to identify IMSI catchers, Stingrays, forced network downgrades, and abnormal tower behavior.
Each unit is sourced from enterprise liquidation and restored by STS Technologies LLC through a full refurbishment process including hardware inspection, battery testing, charging validation, modem health checks, Wi-Fi verification, and a fresh RayHunter installation.
Why People Use RayHunter
1. To Detect Illegal or Unwanted Cellular Surveillance
The Problem:
Cell-site simulators,often referred to as Stingrays or IMSI catchers—can force your device to connect and quietly collect identifiers from every phone nearby. These tools have been used by agencies such as ICE and other law-enforcement groups, sometimes without public notice or proper oversight.
How RayHunter Helps:
RayHunter monitors LTE control-plane signaling and alerts you when a potential simulator is present. This gives you a chance to protect yourself, power down devices, use shielding (Faraday bags), or document the incident for legal or research purposes.
2. To Reveal Secret or Warrantless Surveillance Activity
The Problem:
Some agencies have historically deployed Stingrays without warrants and without disclosing their use, even to courts, attorneys, or the public. These devices are often used before raids or sweeps, and the communities affected typically have no way to detect them.
How RayHunter Helps:
RayHunter acts as an independent early-warning system. When suspicious activity is detected, users can document it or share the data with organizations like the Electronic Frontier Foundation (EFF). This contributes to transparency, community awareness, and legal accountability.
3. To Protect Against Criminals and Foreign Actors
The Problem:
It’s not only government agencies that use this technology. Criminal groups and foreign intelligence actors have deployed cellular simulators to track individuals, harvest identifiers, or initiate spoofed messages to trick victims into fraudulent transactions.
How RayHunter Helps:
RayHunter alerts you to the presence of any cell-site simulator, regardless of who controls it. This is vital for journalists, security professionals, business travelers, activists, or anyone who may be targeted for identity theft, tracking, or espionage.
4. To Hold Institutions Accountable
The Problem:
When surveillance technology is used without transparency or proper oversight, it disproportionately impacts vulnerable populations and erodes civil liberties. Communities often have no way to know when these tools are deployed around them.
How RayHunter Helps:
By making previously invisible surveillance visible, RayHunter gives ordinary people, researchers, and advocates the ability to monitor misuse, challenge improper deployment, and ensure that surveillance practices follow the law.
In Short
RayHunter is used because it provides visibility into a powerful, silent form of digital surveillance that can threaten privacy, free speech, and due process. It gives people a way to understand what is happening around them—and to protect themselves and their communities.
What RayHunter Detects
RayHunter provides real-time monitoring for:
• IMSI catchers
• Cell-site simulators (“Stingrays”)
• Forced 2G/3G downgrades
• Rogue or misconfigured towers
• Suspicious mobility or tracking events
Analysis is available through the built-in dashboard at 192.168.1.1:8080.
Device Features
• Real-time IMSI catcher and Stingray detection
• Visual alert system for safe vs. suspicious activity
• Web-based interface for viewing logs and settings
• LTE support up to 150 Mbps
• Compact and portable: 4.41” × 2.56” × 0.69”
• USB-C charging
• Supports wireless, 4G, and hotspot functions
• Works with any carrier SIM (active service not required for detection)
What’s Included
• Kajeet RC400L(X) hotspot
• Battery
• Back cover
• Power adapter (if available)
• USB A to USB C cable (if available)
• Carry Case (if available, it may be black or blue in color)
• SIM card (inactive, based on availability)
Everything is minimally cleaned, fully tested, and securely packaged.
Note: This means that there is no guarantee on receiving a sim card.
Get one from your carrier ideally. Otherwise Walmart and Amazon have basically any sim card you could need for $5 or less. Refunds will not be accepted on the basis of a sim card being missing, not working, etc.
Note: Due to the nature of how we procure these devices from multiple vendors and resellers, we can not make any guarantee based on the availability of sim cards or the quality / life of the battery. You're buying a complete Rayhunter device with the items as listed. If something is missing that you think you need, be sure to get that separately.
Note: If you want a more premium device, look our New In Box Rayhunter or our Open Box Ray Hunter listings.
STS Extras:
• 10% OFF coupon for your next order
• STS & RayHunter sticker sheets (matte, thermal printed)
All devices are cleaned, tested, and securely packaged.
Important Notes
• SIM required for detection, but does not need an active plan
• No refunds for missing SIMs or bad batteries (availability varies)
• Battery lifespan may vary
• Units may ship as RC400L or RC400LX (functionally identical)
• Contact us if you intend to use it as a traditional hotspot
Supporting Digital Rights
STS Technologies donates 10% of profits from RayHunter devices to the Electronic Frontier Foundation (EFF) to support privacy, security research, and anti-surveillance advocacy.
Software & Legal Disclaimer
RayHunter is an open-source project by the Electronic Frontier Foundation (EFF). STS Technologies LLC is not affiliated with the EFF and does not modify or claim ownership of RayHunter. We only provide pre-configured hardware for users who cannot install it themselves.
This device is for research and privacy-protection purposes only. No warranties on performance, accuracy, or legality of use. Buyer assumes all responsibility for lawful and ethical operation.
RayHunter Software © EFF.
