It works also with DC 14V. The delay should be adjustable between 2-8s. I could not find any changes in the delay time while adjusting. It stays around 1-2s delay.
The protection needs 3V at the input to go into protection mode. If the voltage at the input is gone, it does not stay in protection mode.
I checked this protection against a cheap china protection (with LM7812) and found out, that the cheap does a better job. Protection already at 1.5V and stays in protection mode if the voltage at the input is removed. This is a far better behavior, because if it goes into protection mode, then there is something seriously wrong.
I also do not like the 3 pin speaker terminals. 4 pin terminal would be better.
Based on this i do not recommend this expensive protection board. It works, but there are better choices.