Most advanced reactive load box on earth, period !
I had a journey with reactive load boxes trying to tame the 'loud' of high-watt amps, using the Rivera Rock Crusher, excellent and sturdy load box, with some limitations in recording capabilities, the Two Notes Torpedo Captor, excellent if you need only one impedance and compact design (choice of 4, 8, or 16 Ohms), and now the universal and effectively premium UA OX Amp Top Box with WiFi connection to a computer or iPad to monitor the settings.
It is indeed the best on earth at its price.