The Suhr Reactive Load “…takes the place of your speaker cabinet in your signal chain. It provides an 8Ω load for your tube amplifier (maximum 100 watts), and produces a balanced and unbalanced signal that interfaces with recording devices, effects, and power amplifiers.”
So this product is not an attenuator it just acts as a load for your amp so that you can run it silently into your DAW and use impulse response cabinet emulation for recording or a cabinet emulator hardware device such as the Two Notes Torpedo C.A.B. Also as Pete mentions in the video comments, you could run one of your amp outputs to a speaker cab and the other to the reactive load which would halve your output and attenuate the output although you might need to consult Suhr or your amp manufacturer before doing this, just in case.
Specs:
Input Impedance: 8Ω
DI / Line Out Level: +4 dBu at 7 watts input, maximum level setting
Balanced Line Output Impedance: 10KΩ
Unbalanced Line Output Impedance: 10KΩ
Maximum recommended input power: 100 Watts RMS