Wireless door /window contact designed with SAWF for stable wireless alarm signal transmittance. For door /window sensor, easy installment, For home security and home alarm, intrusion detection to prevent crime. <br> <br>Features:<br>1. Low power consumption with static current less than 5uA.<br>2. With low battery voltage indicator.<br>3. Wireless emit distance in open area is about 100m.<br>4. KS-21AW is used with KS-258B, KS-858, KS-898 (Frequency 433.92MHz)<br> KS-20BW/CW is used with KS-298, KS-998 (Frequency 315MHz)
