1Using touch sensor button, which is generous and nice-looking, also can save electricity. 2Rainproof cover design, waterproof and moistureproof, which can protect the service life of the machine 3Unlocking function (the unlocking interface is suitable for DC 12V normally open/normally locked lock), and it comes with electric control lock. 4The doorbell is equipped with a exit button interface, it is practical. 5An outdoor machine can support up to 5 mobile phone users.