Hoe werkt deze afluisterzender precies?

U plaatst een werkende simkaart in het verborgen compartiment van de adapter. Wanneer u het bijbehorende telefoonnummer belt, wordt de microfoon geactiveerd en kunt u live meeluisteren zonder dat dit hoorbaar of zichtbaar is.

Is deze zender ook geschikt om geluid op te nemen?

Dit apparaat biedt enkel live meeluisteren via GSM en heeft geen opnamefunctie. Wilt u opnames maken, bekijk dan onze modellen met geluidsopnamecapaciteit.

Werkt deze zender ook wanneer de stroom uitvalt?

Ja, dankzij de ingebouwde batterij blijft de zender tot 2 uur actief in luistermodus of 24 uur in standby. Voor continue werking is netstroom wel aangeraden.

Kan ik meerdere telefoonnummers instellen?

Alleen het vooraf ingestelde beheerdersnummer kan verbinding maken. Dit voorkomt ongeautoriseerde toegang tot de geluidsinformatie.

Hoe weet ik of de geluidsdetectie goed werkt?

Wanneer u de geluidsalarmfunctie activeert via SMS, zal de zender automatisch bellen zodra er geluid wordt gedetecteerd in de ruimte. U ontvangt dan een inkomend gesprek van het apparaat zelf.

SIM card listening module - 5V adapter

SKU	7038

Pros and cons :

5V USB adapter function works.
Any SIM card can be used.
Alarm function by ringing when sound is detected.
High quality from the EU.

Due to the adapter design, the applications of the listening device are limited.

The SIM card listener module in USB adapter (5V/2A) is a fully functional charger with an invisibly integrated audio transmitter. You can listen live via the mobile voice network (calls), without an app or Wi-Fi. Thanks to its discreet design—no visible microphone holes or LEDs—the adapter blends seamlessly into any home or office environment. Ideal for temporary observation, internal quality control, or room monitoring (always use in accordance with privacy regulations).

Operation via the mobile voice network

Technically, this works like a modified mobile phone without a screen. You insert a SIM card with call minutes (no data required) into the hidden compartment. As soon as you call the number, the module automatically answers (without an audible click) and activates the microphone for live audio. Optionally, sound detection can be enabled: when sound is detected, the adapter automatically calls back the configured administrator number (whitelist). Location can be requested via SMS command (LBS: cell network position; no GPS accuracy).

User-friendly installation without visible signals

The SIM card tray is located under the hood and can be opened with the included tool. Insert an active SIM card (voice/SMS), disable the PIN code/voicemail, plug the adapter into a wall socket, and call the SIM card number to listen live. No app, Wi-Fi, or other technical setup is required.

Administrator access, sound and vibration alarm

Only calls from the pre-defined administrator number are accepted (whitelist). You can activate/deactivate sound detection and (if supported) vibration alerts using SMS commands. Upon detection, the adapter automatically calls the administrator number, so you're only alerted when there's activity.

Location determination and backup in case of power failure

The adapter can send the last known LBS location via SMS as a clickable (Google) map link. The USB adapter operates continuously on AC power; in the event of a power outage, the internal battery temporarily takes over (approximately 2 hours of active listening or up to 24 hours of standby time, depending on usage).

Craft assembly

These modules are hand-assembled in small batches for maximum reliability. This means the finish may differ slightly from standard 5V USB adapters, but their discrete operation and stability are optimized for professional use.

Key Features

- Hidden SIM card listening module in 5V/2A USB adapter
- Listen live via phone; no app/WiFi required
- No visible microphone openings or LEDs
- Whitelist: Only administrator number can connect
- Sound detection and (optional) vibration alarm via SMS commands
- LBS location determination via SMS (global position, no GPS)
- Continuous operation on mains power + backup battery (±2 hours active / up to 24 hours standby)
- Handcrafted in Europe
- Dimensions: approx. 70 × 40 × 20 mm

Package contents

- USB adapter (5V/2A) with integrated SIM card listening module
- Special screwdriver for the compartment
- Manual

Installation in 2 steps

1. Open the adapter, insert an active SIM card (voice/SMS) and close the cover.
2. Plug the adapter into the wall socket and call the SIM card number to listen directly.

Installing the SIM card listening module in the USB adapter – step by step

Usage and compatibility

Use a SIM card with voice and SMS (prepaid or subscription). Disable the PIN code and voicemail for a seamless connection. Control via calls and SMS commands; no app or Wi-Fi required. Works worldwide where there's mobile coverage and your SIM card supports roaming.

Legal use and privacy

Use this product only within the applicable privacy laws. Applications include internal security, quality control, or on-site test setups. If in doubt, consult legal counsel.

Buy SIM card listening module in USB adapter at Sitcon

Sitcon has been providing reliable surveillance and security solutions since 2007. Our products are extensively tested. Visit our stores in the Netherlands or Belgium for a demonstration and advice, or order online with discreet delivery.

Frequently Asked Questions about the USB Adapter with SIM Card Listening Module

How exactly does this audio transmitter work?

Insert a SIM card with voice/SMS functionality into the hidden compartment. Call the number; the adapter will automatically answer (no audible click), and you'll listen live through the built-in microphone.

Does this model have a recording function?

There is no internal recording. You can record via an external telephone recorder (e.g., Sitcon SKU 7004) on your own phone while listening in.

Does the adapter work in the event of a power outage?

Yes. The internal backup battery provides approximately 2 hours of active listening or up to 24 hours of standby time (indicative). For extended use, AC power is recommended.

Can I set multiple numbers?

The whitelist supports one or more administrator numbers (depending on the model). Only these numbers can connect; other calls are rejected.

How do I set up sound detection or vibration alert?

Activate/deactivate functions via SMS commands according to the manual. Upon detection, the adapter automatically calls the administrator number.

Does this also work abroad?

Yes, as long as your SIM card supports roaming and there's mobile coverage. Check coverage and rates per country beforehand.

Which SIM card do I need?

Any standard SIM card with voice/SMS (prepaid or subscription). Disable PIN and voicemail for stable, automatic call acceptance.

Is the adapter visible as a listening device?

No. There are no visible microphone holes or LEDs, and the USB charger functions normally, making it completely unobtrusive.

Does this system require WiFi or an app?

No. All control is via phone calls and SMS commands. This increases reliability and makes the solution independent of local networks.

How accurate is the LBS location determination?

LBS provides a general position based on cell phone data (not GPS). For exact coordinates, a GPS-enabled model is required; this model reports an approximation.