An 868 MHz band amplifier from Aliexpress. Marked AB-IOT-868.

https://www.aliexpress.com/item/1005006756311325.html

Amplifier:

1. The product is a two-way amplified TDD working mode (that is, the transmit power and receiving sensitivity will be amplified equally);

2. The working voltage is 3.6V-6V;

  Current requirement for power adapter(Not included) : Max.  0.72A

3. This product is highly professional, and wireless communication is greatly affected by the environment. We only guarantee that all parameters are measured by the instrument.

Bi-directional amplifier. Built in TX switch on signal, should be >=1dBm, but threshold is -2dBm. Alternative, switch with SW pin, high for TX. Remove resistor first. 850MHz-930MHz

LEDs: Green RX, Blue TX.

Operating Voltage ：AB-IOT-868-A： 5V（4.75V-5.25V）

Working current ： RX status ：10mA（±3mA） TX status ：≤720mA

Adjustable gain When the potentiometer is turned counterclockwise to the limit, the gain is 5dB； When the potentiometer is turned clockwise to the limit, the gain is 11dB.