Currently, MQTT Client supports the following specifications:
MQTT 3.1.1: http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html
MQTT 5.0: https://docs.oasis-open.org/mqtt/mqtt/v5.0/mqtt-v5.0.html
You can select which is the version which will use the MQTT Client component using MQTTVersion property.
MQTT 3.1.1: TsgcWSPClient_MQTT.Version = mqtt311
MQTT 5.0: sgcWSPClient_MQTT.Version = mqtt5