I have been trying to find out what this device is, as it says Dcc in on one end and out on other, I was told it was a snubber but can't seem to find any more details on it. The stop button on Z21 is configured to cut track or in this case accessory power, which it did but on reapplying power there is a large spike momentarily in voltage. I measured the voltage from the Z21 without the rest of the layout connected. The multimeter I have is unable to record the max voltage in time, I have some at work which will, just wanted to know if this was normal?