Feature: Wireless mini Microphone, clip-on Lavalier Microphone easily for use. It is ideal for Teaching, Conference, Monitoring etc. Specification: Frequency response: 80-12500Hz Effective distance: approx.20m/65.6 ft Transmitter Power: 1x 6F22 9V battery(battery not include) Transmitter size: approx.100mm x 63mm x 21mm/3.93 x 2.48 x 0.82'' Receiver power:1x AAA 1.5 battery(battery not include) Receiver size: approx. 72mm x 44mm x 14mm/2.83 x 1.73 x 0.55'' Gross weight: approx. 110g Operation Manual: 1. Open the bottom cover of transmitter, put the cell and close the bottom cover. 2. Insert the microphone connected cable into the hole of transmitter. 3. Open the battery jar of the receiver, put in on and then close the battery jar. 4. Switch on all the receiver, it can be operated when the display lights on. Note: 1. If the transmission of sound is high and low, the first consideration is to replace the battery, if it is not valid, please send it to the designated service center. 2. If not using for a long time, please pull out the battery. 3. If the microphone is too close to the receiver, it will produce a considerable noise. Please note the distance. 4. Due to different producing batches, product details might be a little different. If you minding the difference, please buy it carefully. 5. Please allow 1-3mm differs due to manual measurement Include: 1 x transmitter 1 x receiver 1 x clip microphone 1 x instructions