The 'T' in the model-type (TB-2T) stands for 'telleverk' in Norwegian, which means counter. So this model is equipped with a counter. However, it is not the type of counter you first may think, with the rolling digits, but a clock-like counter with two hands.
Strange thing with this item: It has another model's type-label!
And practically enough, it has the circuit schematic glued onto the bottom.