Features:* One Magnetic Sensor can match with at most 8 remote controllers freely.* One remote controller could control several magnetic sensors.* Excellent Home use product， Tiny and fashion.* Volume: 110DB.* Alarm and door bell function for your option.* Low energy and long work time.* Simple install.Specifications of Magnetic Sensor:Voltage: 3V AAA*2pcs(Not Included)Stand-by Volume: 100uAAlarm Volume: 30mAFrequency: 433MHZAlarm Response Time: 200msStand-by Time: 8-12monthsMagnetic Sensor Size: Approx.8.5*5.2*1.5cm/3.35*2.05*0.59inSpecifications of Remote Control:Voltage: 12V 12V27A*1pcs(Included)Stand-by Volume: 1uAWorking Volume: 15mAStand-by Time: 8-24monthsRemote Control Distance: 20m/65ftRemote Control Size: Approx.5.7*2.9*1.0cm/2.24*1.14*0.39inPackage Size: Approx.11.7*7.0*3.9cm/4.61*2.76*1.53inPackage Weight: Approx.86g/3.04ozPackage List:1 * Magnetic Sensor(batteries not included)1 * Magnetic Stick1 * Remote Control1 * User Manual