GU10 Wifi bulb : No hub required GU10 Zigbee bulb : Zigbee 3 hub/gateway requiredZigbee Bulb should paintings with bridge,zigbee gateway or zigbee hub;Note : If you would like connect yandex alice voice leadership with ewelink zigbee bulb ,please you should paintings with ewelink gateway instead;Wifi bulb can hyperlink with yandex alice straight ; Base: GU10 App: eWelink App Wireless type: Zigbee 3 / WiFi Rated power: 5W Voltage: AC 100-240V 50/60Hz Color : RGB+2700K+6000K Dimmable:Yes System Supported:IOS/Android Luminous Flux:350lm Service life: ≥ 30000H Functions 1 Remote control; 2 With Alexa,Google Assistant; Support control colours and brightness 3 management with Alexa,google assistant ,yandex alice ,smartthings etc.; four Control; Control led bulbs on one telephone 5. eight Scene choice modes;6 Shutdown and timer; Question: 1:Is a hub required to attach the downlight? A:The eWelink Zigbee edition calls for the use of a Zigbee 3 Gateway connection use it with linked zigbee hub; 2:Does it work with Alexa /Google Home? A:Yes,it is also compatible with Alexa and Yandex Alice for simple voice control. 3:If the light has been powered off by means of the wall switch,will it retain its settings when energy again on? A:Yes,the comfortable will hold the ambience as before for the memory function. 4:Can this be used manually(without wifi) with a dimmer switch? A:Yes,When there's no Internet connection, the APP(eWelink) can management the sunshine bulb in the course of the bluetooth signal.