Sonoff RE5V1C

Features :

Nano Size 
Dry Contact Output
Low Power Supply – 5VDC low voltage input
2 Working modes – self-locking and inching mode
LAN Control – Turn on/off the device even when WiFi has no Internet access
App Support – Free iOS and Android mobile App eWeLink
Remote ON/OFF–Turn electrical devices on/off from anywhere
Sync Status–Real-time device status provided to App
Timing–Set scheduled/countdown timers to turn on/off at specified time
Share Control– Control your smart home together with your family
Scene–Turn on/off a gang of devices with one tap
Smart Scene–Triggered on/off by temp, hum or other environmental conditions from sensor
Compatibility –Works perfectly with Amazon Alexa, Google Assistant, IFTTT, Google Nest
Long story in short, it’s a 5V wifi inching/selflock relay module by SONOFF.
Just like a standard SONOFF switch, you can use it to work with eWelink app, Amazon Alexa, Google Home, IFTTT..etc.
The 5VDC input, nano size and dry-contact output makes it different from traditional SONOFF product, there are two working modes for the product: inching mode and self-locking mode. users can switch these two modes on eWeLink app.when the module is switched to the self-locking mode, users can turn on/off the connected appliance instantly. when the module is switched to the inching mode, users can press the ON/OFF toggle button to turn on or off connected devices.
The product enables remote control of home appliances through the mobile application eWeLink, available on both Android and iOS. Supported functions include:

Remote turn on/off
Timing Schedules
Device Sharing
Group Management

Supports status tracking: device status is timely provided to eWeLink.
Supports max 8 enabled scheduled/countdown/loop timers.
Works with Amazon Echo, Echo Dot, Amazon Tap
Works with Google Home, Google Home Mini, Google Nest
Works with IFTTT