The R600 SIM GSM Ear is a cellular listening device or "bug" manufactured by First Electronics in Taiwan. You call the number assigned to the inserted SIM card, and the R600 automatically answers without ringing. You can then listen to what's being said in its vicinity. The R600 can only use SIM card-based GSM cellular networks, such as AT&T and T-Mobile.
Insert the SIM card into the SIM card slot on the R600 with the contacts facing down. The SIM card's clipped corner should be on the outside. The red light will flash if the SIM card has been inserted correctly.
Place the R600 in the desired listening area.
Dial the number of the SIM card in the R600 on a telephone.
The R600 cannot use GSM service on 850MHz. It requires 900MHz, 1800MHz or 1900MHz.
Surreptitious use of this device may be illegal depending on state and local laws. Use at your own risk.