Control Your Lights from Anywhere. Install the smart WiFi LED bulbs as easily as a standard light bulb. These bulbs connect to your home WiFi easily without a hub. The Sengled Home App allows you manage your lights, including brightness adjustment and schedule setting and also scene and energy monitoring anytime, anywhere. You can use simple conversation to control yours lights when paired with Amazon Alexa or Google Assistant. Features: No Hub Required: Connect the Smart WiFi LED bulb to your 2.4 GHz WiFi network with the Sengled Home app (iOS/Android) to get started Smart Lighting: Turn lights on and off, dim and brighten and more with the Sengled Bluetooth App Voice Control: Connect the bulb directly to your Alexa or Google Assistant device and control your lights via voice commands Create Scenes and Routines: Set scenes, change colours or put your lights on a schedule, whether at home or away. Mesh network: Use multiple bulbs to form a mesh network for extended control range Specifications: Dimensions: H:10.0 x W:12.0 x D:13.0 cm Guarantee:2 Years Model Number: W21-U31W4P