Brunsviga 13 ZK
One of my very first pinwheel calculators, and an ebay find. I was delighted to discover all the green and red coloured details when cleaning it. In ZK , the Z stands for full tens' carry in the counter register, K stands for a combined clearing of counter and revolution, and input register. You can also have machines designated R, which stands for back transfer from result to input register. This machine does not have that functionality.
