Optimus Trapper 81 purchased on ebay. Stove had never been fired and pot lifter was still in its plastic bag. Unfortunately the box was pretty mangled. The year is unknown but it’s one of the older ones, lacking the weep hole that indicates when you’ve added the maximum amount of alcohol it can hold. The red fuel measuring cup doesn’t have the sticker seen on some kits, explaining that it holds 1 dl and you should fill an empty stove with three measures. Oddly, that procedure contradicts the printed instructions which say that maximum fill is 250 ml. Perhaps the 300 ml fill became the standard after the fill indicator was added. The stated weight of the stove is 970 g but my postal scale put the complete kit at 941 g. Component weights are as follows, in grams: Base 327 Windscreen 97 1.9 l Pot 126 2.0 l pot 128 Pan 152 Pot Lifter 58 Plug & Filler 30 Strap 23 The pots are listed as 1.9 and 2.0l. They lack volume indicators but filling them to just below the beltline takes 1 l. For storage, the smaller pot nests snugly inside the larger but reverse the order and they can be used as a double boiler. The alcohol stove is built into the base, unlike a Trangia 25 or 27 which utilize a separate brass burner. Also unlike the Trangia, the flame is adjusted via an external lever in the base. Moving the lever slides a plate across the circular opening at the bottom of the burner, acting as an air shutter. More air allows the fuel to burn hotter and faster, and closing the shutter completely adjusts the flame to a minimum. If the shutter is closed before the stove fully warms the flame may accidentally extinguish. Combustion air for the flame comes from two sources, up the center through the shutter and in from a circumferential gap in the base plate just below the top of the burner. This creates a dual flame front, which probably improves efficiency. Fuel is held via absorption into a fiberglass like foam material that surrounds the burner tube. Filling is accomplished by inserting the red plastic fill adapter into the tube and pouring fuel down the center. The adapter has a bottom to it and holes in the side. The fuel simply wicks into the fiberglass. The stove base becomes surprisingly warm during use, again unlike a Trangia 25/27. Once the stove cools, the red plastic fill plug can be inserted and capped to retain leftover fuel for the next use. A couple of burn tests with water straight from the tap boiled 1 l in 10:30 and .5 l in 5:30. An additional test was run with .5 l and the shutter only 50% open. Surprisingly the boil time remained the same at 5:30. It’s a little surprising that this cook set is no longer produced as it offers an experience similar to the Trangia 25 but with the advantage of much easier flame control and lighter weight. Some comparison pics with the Trangia 25 and also the Svea 123 powered Sigg Tourist and Optimus 88 kits.