Usage Tips:1. Two-way ringtone call, ringing ringtone. 2. Two-way intercom, press and hold the TALK button to speak directly. 3. Mobile call, mobile intercom 4. Outdoor open space barrier-free straight-line call distance 500-1000 meters. 5. Slim appearance, thickness is only 18mm, similar products on the market are more than 22mm thick, and it feels good in the hand. Battery 1800 mAh polymer lithium battery, according to normal work 5 times a day, each time, work for about 1 week, The button adopts plastic structure, and the is high-gloss UV process, which feels super good. Intelligent and humanized design, with intercom light and power light display, customers can see at a glance. Put it on the charging stand when on standby, intelligent charging, never power off. Power key--0 gear--indicates shutdown A gear--462 frequency 462 B gear -- 434 frequency. If interference occurs during a call, the two machines switch to A gear or B gear. Power supply: polymer lithium battery Battery power supply: DC5V/1A Working temperature: -20 degrees to 55 degrees Transmission distance: about 1000 meters in an open space, 20-100 meters through a wall, 1st to 8th floor Working frequency: B gear frequency 462MHz A gear frequency 434MHz Working time: about 1 week after a charge Charging time: about 5 hours to fully charge Music ringtones: 38 ringtones Ringtone volume: 3 levels of adjustment (volume adjustment button on standby) Call sound: 3 levels of call volume adjustment (volume adjustment button when the call is working) Colour:Black Material:plastic Package Contents: 1 x Wireless intercom set Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.