Usage Tips:Features: No call charges, the GSM gate opener rejects the call from authorized number then carries out the turn on/off action on the first. So, you can open gate or garage door with a free call from your mobile phones. The GSM gate opener is very simple device which can be used for authorized door access, controlling gates, switching of remote equipment, car parking systems. You do not need to worry the stranger can control your GSM set to open your door. You can protect your assets with low cost. You can open gate or garage door with a free call from your mobile phones. You can set the device by APP, you can also can open the door quickly by shaking your phone. Based on GSM network, it can be widely used in doors, guardrails, shutters, parking systems, household appliances, computer rooms, greenhouses, remote equipment switching, industrial remote control, etc. Specifications: Material:Metal Size: Approx.8.2x7.6x2.7cm/3.22x2.99x1.06inches Note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks for your understandings. Package includes: 1x GSM Gate Opener