Wsdcam Wireless Door Alarm Window and Door Open Alarm Magnetic Sensor Pool Door Alarms for Kids Safety Home Security, 110 dB Loud - Door Alarm with 2 Remotes

Troubleshooting steps
If your second remote control did not work, pls check whether it lights up, which means no problem. Otherwise, it is defective. In fact, most of customers told us their remote lit up.
If it does not light up. pls contact us at wsdcamservice@wsdcam.com and we will send a replacement remote in 5-7 days.
If it lights up, you need pair your second remote control.
The program is as below,
Alarm should not in arm mode.
Take out all batteries of the alarm.
The alarm need two batteries.
Pls just put one battery in at first.
When you put the other one into the alarm, pls press and hold the bell button on the second remote.
After you hear a "Bi...", press arm key once.
Then alarm will sound two "Bi... Bi...". It is well done.

Host 2AAA alkaline batteries to operate ( not included )
An 12V/27A alkaline batteries ( included ) of the remote control to operate
Installation:
Select windows and doors to the installation location, with water and cloth to clean the mounting surface, the double-sided adhesive tape on the bottom and then this machine is attached to the clean position
Installed host, and then double-sided stickers magnets host next door or door frame, pay attention to set the magnetic iron arrow at the arrow to the right host.
Ensure close the door the host and the magnet installation distance should not exceed 10mm.
Application Function:
Arming and disarming
Alarm triggered
Emergency functions
When you are at home when you encounter an intruder or other emergency situations, the remote control [flash] is pressed on the key host will ring alarm.
Emergency function keys are valid in any mode.
Doorbell function
Increase the remote control and alarm
You can increase the remote control and alarm depending on your needs see the instruction set