I have one of these as a component of my Magnum system, which also consists of an MS4024 inverter, a Battery Monitor Kit and a Remote Control. You can buy the AGS as a free standing separate unit. The Magnum AGS is set up with adjustable timed relays for pre-start and cranking according to your specific generator's requirements. It starts our circa 1991 Onan 20kw flawlessly. It also has adjustable timing for when to turn off; with the remote, you can adjust this time while it is running, so shorten or lengthen the cycle, very handy. You can select over a wide range what battery voltage you want to trigger it . We have used this extensively over the last 7 months of full time cruising, much of it spent at anchor. While it is very slick, I have some mixed feelings about it. First, you have to remember to shut big loads down (such as air conditioning) before it shuts the genset down. Otherwise the genset is started with these loads almost immediately applied to it with out warm up, in addition to the battery chargers. Second, it will prematurely start if a large temporary draw (typically the microwave) is put on the batteries when their voltage is near, but not at the trigger point. The AGS kicks in when the voltage read at the batteries is below the trigger for two minutes. Third, it makes it easy to not go and check oil and coolant levels and other visuals. To this end, I disabled the existing genset remote start/stop switch to force us to go down and start it manually for when big loads are needed outside of the auto start cycle. And I have it on a daily checklist just in case. Fortunately this is very easy to do on our boat. All in all, this is a very handy device. Magnum's customer service is superb, and their operating and set up manuals are excellent. I don't know if they have made the necessary modifications yet, but the installation instructions weren't quite up to the same standard; given that you can get such good help over the phone or e-mail, it is not a big deal, but I definitely had to avail myself of that help. Their manuals and a variety of other info are readily available on line at the Magnum Energy website. George