This hour meter works nice in my boat. I have a Tiara Open 38 and bought them because every time we wanted to see how many hours my Cummins marine engines have being running, I had to send the keys to the mechanic to open the switch and look in each of the two electronic monitors that are installed in the cockpit's console. Now I just installed one of this meters next to each engine and the mechanic just goes there and knows if the engines needs an oil change or a certain service, without having to ask for the keys.