This particular unit goes from -6 to -16.5dB in 0.5dB steps which is perfect for padding that horn down to the bass. The "coarse" steps are 1dB and the toggle allows for a 0.5dB trim.
Of course it resides on a permalloy core and allows the end user to select the desired impedance presented to the crossover by selecting the shunt resistor.
Wiring is simple with the same 3 connections as an L-pad. More info to come!