Logitech K380 Multi-Device Bluetooth Keyboard 5mp it also has EMC signal

it also has EMC signal input for emergency situation

One-button WPS Bridging

you can tap "Find" to play a sound and the buzzer inside the product will ring 12 beeps to help you locate the position

a 4‑channel hybrid DVR supporting both analog and IP cameras

Logitech K380 Multi-Device Bluetooth Keyboard 5mp it also has EMC signalLogitech K380 Multi Device Bluetooth Keyboard Description: Meet K380. A multi device keyboard with a small footprint and quiet typing for computers, tablets and phone, at home or on the go. K380 Multi Device is a wireless keyboard that connects to all Bluetooth wireless devices that support external keyboards. Take this compact, lightweight, Bluetooth keyboard anywhere in your home. Type wherever you like, on any compatible computer, phone or tablet.