Description:This pair of infrared detector need install them at the opposite positions. There is a infrared area between these two detector parts. When someone passes the infrared region for an adjusted response time, the detector will send alarm signal, great for security system in school, office building, hospital, parking and home yard, etc.Features:Made of high quality plastic shell, eco-friendly, durable and sturdy to use.Create a reliable and invisible infrared beam up to 20 meters.Infra-red frequency: 1.92Khz; Power supply: DC 12V; Wave length: 940nm.Half egg shaped, input: RX 15mA-TX 30mA, operating temperature: -10 to 70Range can be reduced to 30% in bad weather conditions: fog, rain, dust, etc.Specification:Condition: 100% New BrandColor: BlackShell Material: PlasticReceiver Range : Less than 20mInfra-red Frequency: 1.92KHZWavelength: 940nmVoltage: DC 12VInput: RX 15mA-TX 30mAOperating Temperature: -10 to 70Relay Output: 1A maximum 30V, constant open/close, can be set by jumper wireSize (L x W x T): Approx. 76 X 49.2 X 21.6mm / 3 x 1.9 x 0.9inchPackage Weight: Approx. 130gPackage Included:1 x Transmitter1 x Receiver1 x Set of Accessories1 x User ManualNote:1. The best installation height should be more than 20 cm, distance is not less than 2 meters. 2. Infrared protection device should be installed vertically, and at the same level.3. First installing receiver, then installing transmitter. When the off light of receiver is turning off, then fixed it, installation finished.4. Distance between receiver and transmitter need be more than 1m, otherwise it will be insensitive phenomenon.5. Please note that the new type and old type of this product will be sent randomly and make sure you will not mind before ordering..