The STI Wireless Fire Extinguisher Theft Stopper® with Receiver (STI-6200WIR4) offers a unique steel cable operated switch mechanism, to help stop theft and vandalism of fire extinguishers. If the protected fire extinguisher is moved from its normal position, the device emits a piercing alarm (choice of 95 or 105 dB) and sends a radio signal to the included receiver, alerting it has been triggered (1000 foot range, line of sight). This alarm helps draw attention to a fire extinguisher and the vandal will either run or be caught. Additional sensors only: STI-6200WIR. Models without wireless transmission: STI-6200.