IntroductionI was in the market for a new AC adapter recently and thought that I should make the purchase worthwhile. I like the convenience of not having to carry more than one OEM adapter from my apartment to the university library - it's one less thing to pack. The Kensington 120 Watt Notebook AC/DC Power Adapter (model #33197) is a perfect addition for those who need a spare charger that can act as a universal charger for many of your gadgets. While it isn't the smallest of power bricks, it is certainly a lot thinner and lighter than some others.My Acer notebook / Tablet PC convertible only needs a 65W brick, but I chose the 120W because it has versatility in case I choose to buy a larger notebook in the future. As a note, the Kensington 70W sibling is much smaller than the 120W one, but about the same in thickness.In the BoxKensington 120W Adapter (110V-240V)AC Plug & 10' cordDC + Air Plug (12V Auto Cigarette Lighter & In-Flight Use)Proprietary "Tips" for Various Notebooks (N1, N2, N3, N4, N5, N9, N15, J3)Soft Carrying CaseSize & WeightHere's a comparison chart of the Kensington power adapter compared to some competitors: Acer 65W GenericDell 90W GenericKensington 120WSize4.01"x 1.0"x 1.0"6.01"x 2.4" x 1.35"5.6" x 3.1" x 0.66"Weight12.8 oz.13.3 oz.11.4 oz.As you can see, the difference in weight is only ~1.5 oz. That is not much, but when carrying books and other materials along with a notebook, any extra weight is a burden. The size values don't look so thrilling compared to the way Kensington describes them, "40%smaller and lighter than other power supplies." This adapter is larger than my current one, but it does a lot more too. For people whose notebooks draw more than 100W, the 60-70W adapters are simply not an option. In a sense, comparing 120W adapters with 65/90W ones is like apples and oranges, but it goes to show how well built the Kensington really is for its abilities.FeaturesThis adapter can be used anywhere, by almost any power source. You can use the AC aspect anywhere in the world (like all non-Mac A/C adapters). The DC portion is a little deceiving - it doesn't mean that you can hook up a battery source, if you are wondering. DC refers to being able to draw power from your car's 12V battery via the cigarette lighter. Another great feature about this adapter is its use in a plane, in-flight. Apparently, airlines provide a 12V power source on the arm of the seat. I don't know if this is available in coach class (so it's of no use to me) but it is a great feature for business-people on the go.Another nice feature is that the Kensington has "overvoltage, temperature and short circuit" protection, which probably acts as a semi "surge" protector. Of course, one can't expect it to be full surge protection. While I can't attest to this functionality, it's something to comfort us in the purchase.(view large image)"Smart Tips"The included tips are N1, N2, N3, N4, N5, N9, N15 and J3. These tips are great for many mainstream notebooks. The J3 tip is an added bonus for iPod users. Right out of the box, many Compaq, Dell, Fujitsu, Gateway, HP and Sony Notebooks are supported. Other brands are left on the wayside as far as instant gratification. The Acer I have needed tip N14.Kensington promises "1 Free Tip" to all who purchase their power adapter. There isn't anything mentioned about this except for one line of fine print on the back of the box. I emailed Kensington tech support and they were prompt in replying (which would have cost around $15, including shipping), but I received it only after two weeks time! I wish that there weren't any tips included and that the cost of the power supply was ten or fifteen dollars less. Most people are not going to use more than one tip anyway, even if their notebook is supported by the provided tips.The Kensington slim adapter has a proprietary system of delivering a set amount of power to your device. As such, it can support all electronics that use far less than 120W. Many tips look alike, and unsurprisingly may fit into your notebook. However, if they are meant for other manufacturers your unit will be fried. Getting the right tip is essential and for those who own multiple notebooks, remembering to switch tips is critical.Keep in mind that even though the Kensington can theoretically support any small electronic device, the tip availability has to exist. If you want to power your PSP and your cell phone, you have to pony up for the tips. You can see what tips are needed, and their cost below.Find Out What Tip You Need (and compare it to the above list of tips provided): SmartTip Selector(view large image)Heat & AnnoyancesThis adapter gains a moderate amount of heat during use, but I suspect that is because the Acer I own does not task the unit by more than half of its output capabilities, so it would get much warmer if used on a 15" or 17" notebook.The AC power cord Kensington supplies is too short, resulting in a small distance between the adapter and the wall. Kensington claims that this is to help with heat dissipation. I don't find it to be much trouble, although other users have complained as it can leave the adapter dangling in a haphazard manner (see the picture below). The soft case is a bit small if you want to carry all the tips and plugs, but since I won't be, it just barely fits. I will end up just not using the case.The power cord is too short for most outletsValueI paid $39 for a new Kensington 120W brick on eBay, with free shipping. I could have spent about that much getting an OEM adapter or a third-party comparable one. I consider the Kensington to be a deal since I can use this on a variety of electronics and notebooks, in a car or in-flight. There is an optional accessory to this power supply that allows charging of two devices at once. If I was not sure that I was going to upgrade my notebook in the coming few months, I would have just purchased the 70W Kensington adapter, which will be more in line with my current Acer brick in terms of size. Generally, I am pleased with this power supply.ProsConsVersatileRelatively light and thinWill power a multitude of devices (Notebooks, PDAs, DVD players, cell phones, digital cameras, MP3 players and gaming devices) and simultaneously as well.One "Free" TipOne Year WarrantyLarge in sizeIncluded tips are for mainstream notebooksIncluded case is too smallExtra tips are very expensive (~$9.99 + $5.70 shipping, each)A note of caution > Do not attempt to use this item if your notebook needs more than 120W of power. Some large notebooks (generally 17" and larger) need more than 120W of power, and using this item will damage your notebook.