1. Frequency Reader Counter is a test frequency wireless remote control apparatus that can accurately test the frequency of the remote-controlled device and clearly display the result. 2. The Frequency Counter test method is very simple; just bring the remote control device close to the frequency counter to accurately measure the remote control frequency. (Valid test range is not more than 10cm). Type: 250-450MHz Frequency Reader Counter Wireless Frequency Counter Frequency Counter Features: 1. Portable frequency counter 2. Ideal for electric door controller manufacturers, automatic door manufacturers, and other applications 3. Equipped with a 4-digit screen for clear result display 4. Easy to use and carry Effective Test Range: 250MHz to 450MHz Valid Test Range: Less than 10cm Powered by a 9V 6F22 battery (Not included) Operation Voltage: DC9V Standby Current: 40mA Operating Current: 51mA Size (L x W x D): 9.3 x 5.8 x 2.4cm / 3.7 x 2.3 x 0.9 inch How to use: 1. For measuring wireless remote control frequency, press any key on the remote control within the sensing zone to display the frequency. 2. For measuring infrared remote control or other transmitters, point the remote control toward the infrared receiver (INPUT) and press any key. If the IR indicator light turns red, the remote control transmitter is functioning. This wireless Remote Control Detector is for testing and study purposes only. Users must comply with all applicable laws and regulations in their country. Not intended for illegal use. Color: Gray & White Material: Plastic Package Contents: 1 x Frequency Counter 1 x Battery Connector Note: Light reflection and different displays may cause the color of the item in the picture to vary slightly from the actual product. Measurement error allowance is +/- 1-3cm.