I have seen the northern tool ones and they sure look like the same thing in the pictures. A buddy of mine has them on his processor and without popping them open, they look just like my HF ones. One of these days ill tare his apart and see what the insides look like.
For many that only have 110 to 120 volts on thie line you probably will not have to worry, but if there is a spike in the line volts you can and probably will pop a cap. If you read around on thses pumps lots of people talk about them frying. Thought I would share an experience of one frying. Ill take pics tonight