This two-way GSM audio device allows you to remotely monitor environments by connecting via phone call. Simply insert a GSM SIM card and program it to your desired number for easy setup. The device features a built-in microphone with a listening range of up to 7 meters, enabling you to clearly hear surrounding conversations when you call it.Key features include:- Call the device anytime to listen in on real-time audio from your chosen location- Sound-activated calling function automatically alerts you when noise is detected- Tri-band GSM support (850/900/1800/1900 MHz) ensures wide network compatibility- Built-in 400 mAh rechargeable lithium-ion battery provides extended operation- USB charging cable included for convenient power replenishmentIdeal for use in various indoor settings such as offices, living rooms, or conference areas. The compact design allows for discreet placement.Product specifications:- Function: Tri-band GSM two-way audio monitoring device - Material: Molded plastic - Color: Black - Microphone range: 57 meter radius - Battery: 400 mAh rechargeable Li-ion - Standby time: Up to 1621 days (depending on usage) - Active voice monitoring mode: 58 days continuous use - Dimensions: 4.3 x 3.2 x 1.4 cm Package includes:- 1 x Audio monitoring device - 1 x USB charging cable - 1 x User instruction manual Note: This product is intended for lawful use only. Users must ensure compliance with all applicable local, state, and federal laws regarding audio recording and surveillance. The seller assumes no responsibility for illegal use or unauthorized installation. Check your countrys regulations before purchasing or operating this device.