magnetic door sensor

home alarm system with alarm verification direct from Wanlin Fire Protection — 12-year factory experience, WL-HS102 certified CE/FCC/RoHS/REACH/ISO9001/NFPA 72. Key specs: 4G LTE + WiFi + GPS Medical Alert Integration, 4G + WiFi + GPS + SMS + Phone Call + Push + Two-Way Voice. No monthly fees, 4G cellular backup, DIY installation, expandable to 50-100+ senso···