Linkage with other smart devices No battery replacement required for 1 years Used directly without tools Moisture approvedmanufacturing process Faster feedback speed Specifications: Zigbee Gateway/Hub: Required Operating voltage: 2.3-3.3V Detection accuracy:Less than 5mm Battery model:3V CR2032 Life of battery: 1 Years Working temperature:-10--45 Celsius Relative humidity: 0-95%(Non-condensing) Detection distance: 10-30m indoors, 30-50m outdoors (only as reference) App: Tuya Smart/Smart Life Gateway: Tuya gateway Colour:White Material:ABS Size:5 x 2.5 x 1.1cm Package Contents: 8 x Smart Contact Detectors Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.