I've got one of these. Not as easy as a jug to measure and if you overdose, that's it, it's in the tank, no second chances. With a jug you can tip some back in the oil bottle.
I use it instead of an oil bottle as it's cleaner. Only issue is it isn't as easy to pour a bit of oil back in from the jug as an ordinary oil bottle.
But I still use a measuring jug as it's actually more accurate and I can pour some back if I overfill a bit
I use 6 of these.One bottle holds enough for 2.5 Litres at 3%,thats 3 litres of fuel.The bottles fit neatly into the front of my toolbox along with my tools and waterproofs.http://www.ebay.co.uk/itm/5-Empty-Body- ... SwzgBY2nYg