Main Features:  -The Newest IPS UI Interface: We have added IPS technology to the UI interface of this H501-4G product. The 'IPS', called 'Super TFT', is an upgraded version of TFT. Compared with TFT: The 'IPS' has a large viewing angle. Color reproducted is more accurate. No water ripples when touched. Environmental protection and energy saving.  -600MHZ High-Speed Smart Chip: This H501-4G uses 600MHz High-Speed Smart Chip. The operating speed of this H501-4G is 12 times that of other similar alarm hosts(50MHz). So the running speed of this  is faster and smoother.  -12mm Ultra-thin body:  -Support OTA online upgrade: We will continue to release feature updates and stability upgrades, and you can get free updates via OTA online upgrades when necessary. Note: Most similar products do not have OTA online upgrade capabilities, and can only repurchase new product to obtain upgrades.  -Bulit-in 10 languages: English/ Nederlands/ Spanish/ Russian/ French/ Polish/ German/ Italian/ Portuguese/ Chinese.  -Support Alexa and Google assistant, Tuya Smart & Smart Life APP :  -Support IOS APP and Android Mobile:  -Two- Way Talk Function: Family members can communicate and talk through this H501-4G. When the thief enters your home, the H501-4G will automatically call you. You can remotely stop the thief and let him leave your home.  -5 Groups Preset Alarm Phone Numbers: SMS on/ off and dial on/ off can be set respectively: The user can set five different phone numbers in the H501-4G. When an intruder enters your home, the H501-4G will automatically call these five phone numbers. At the same time, H501-4G will also automatically send text messages to these five phone numbers. -Low Battery Alarm Reminder Function: When the battery of the H501-4G accessories (such as door sensor, infrared detector) is low, H501-4G will sound an alarm to remind users to replace the battery.      Note: Accessories support hosts of all staniot models.