Does the motion sensor has a selectable timer (e.g. 15-20 minutes)?
No. All our motion sensors do not have timer.
In the SK698 and SK602, once the motion sensor is triggered, the receiver will sound the alarm for 10 seconds (except Ding-Dong sound).
In the SKQH652, the alarm will sound for 25 seconds. The motion sensor detection interval is 5 seconds.
Please take a look at the SK633, SK634, and SK618 if you need more advanced features.