Mars 83904 was a 15 minute install and invaluable in terms of protecting the value of my home furnaces. Recommended at a rating of 4 — would give it a 5 but (luckily) I haven’t had to see how it performs with a power bump.

This is just a surge protector. If I’m reading this, I give it an average. As for kool.net quick service quick ship, I give us a five stars

This product is great. I’ve installed a few and it did its job.

I am pleased with MARS model 83904 surge protective device; it is made well with the hard plastic case. It should work well for protecting the circuit board in my furnace, it was simple enough to install if you are mechanical inclined, and If a person use some common sense.

Easy to install, fast shipping, trusted seller, piece of mind and protection for sensitive equipment. Definitely would recommend and would buy again

This the second 83904 surge protector I purchased. So far each of them have worked fine.

I can't vouch for its ability to perform, but was an easy installation. Based on the quality of your other products I expect the same performance.