Works perfectly, and heats quickly. It is thermostatically protected, so that it heats the coolant to a preset temperature, without overheating. I got this to replace a failed unit on a tractor, so installation was easy. The hoses already were plumbed, all I had to do was remove the old one, and install this one. It comes with new clamps, and a couple fittings that would be helpful in a new installation: a mounting bracket, a tee fitting, (to tap into a heater hose), and a fitting with threaded ends, (to connect to a threaded hole in the water jacket of your engine block), and a simple instruction/installation sheet. You supply your own tools and any extra hose you may need.Now my tractor goes from a sluggish start at 30 degrees to starting right up at 15.I have one of these, and another rated at 1500 watts, and unless you have something BIG to start, like a 100 HP tractor, I’d suggest going with this one, as it seems to be all I will ever need on an 80 HP tractor, and draws under 10 amps, so you can run two at a time, on a single 20 amp circuit. The 1500 watt heater draws somewhere around 13 amps, and almost needs its own circuit.