The device should be installed with your local 4G SIM card. Then you can control the device On Off remotely by SMS, Call, PC web and App (WLTE Control).App and PC web communicate with the device via 4G data .SMS and call control is based on SMS Call network channel.Call control supports 99 authorized master numbers Max.With the 4G LTE network, you can install the device anywhere with 4G network coverage, perfectly solved the weakness of WIFI network distance limitation.Web control ( in 4G data mode): control equipment via a web browser of PC.User can use the web browser to send On/Off to controller, but can't modify setting and push notification. Please do related settings on App.App control via 4G data :The App ( WLTE control ) has multi-functions: control relay on/off, timing control, centralized management control, sharing devices, time correction etc.,Set:A version: No power off alarm function.Plug Type:EU Plug,it applies to Indonesia, Germany, France, , Italy and so onVoltage: AC220VMaterial: Metal+Plasticcolour: As shownPackage Contents:1 x Smart Relay Switch (no power off alert)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.