UEi HUB4 and HUB6 HVAC Smart Probes Review Posted on: 29 August 2018 By: Marc All HVAC service techs remember that Testo has started a “Smart Probe Revolution” in 2016.Tags: UEi HUB4UEi HUB6UEi HUB 4 reviewsUEi HUB4 or HUB6UEi HUB 6 reviews UEi Smart ProbesUEi Refrigerant Smart ProbesUEi HVACUEi HVAC Smart Probesuei instrumentsUEi HUB4 Smart Refrigerant Charging AC System Diagnostic KitUEi HUB6 Smart Refrigerant Charging KitHVAC Tools