These one litre Erlenmeyer flasks work beautifully as wine decanters and also look cool, which is arguably just as important. We should probably not say this but they also make for great vases.
Why do we decant wine?
The short answer is to give the wine some air. After being cooped up for however long it has been in bottle, the oxygen exposure can allow a wine to unwind and settle into itself and goes a long way to improving the experience of drinking it by enhancing the flavours. With very old vintages - and some of the funkier, unfiltered stuff - decanting also helps to leave sediment in the bottle.