If you are selling knitting needles on ebay, there are a few things you need to state in your listing. Size, Length, Material, Make and Condition.
Imperial sizes, also called UK sizes, where size 14 is very thin and size 000 is very thick, are preferred by some knitters, but it would be unusual to find these in an unused condition.
Metric sizes are marked in millimeters - mm. 2mm is very thin (equivalent to size 14 imperial size) and 10mm is very thick (equivalent to imperial size 000).
The 4 most popular lengths are 25cm(10 inches), 30cm(12 inches), 35cm(14 inches) and 40cm(16 inches).
The most common materials used for knitting needles are plastic, metal and wood. Generally smaller needles are metal and at around size 5.5mm, they are made from plastic.
Some buyers collect certain makes, so if there is a name on the needles you are selling, include it in the listing.
Knitting needles should be clean, straight and not chipped. Sellotape can be really difficult to remove from some types of needles, so tie in pairs with ribbon. Even rubber bands can leave marks on the needles as the rubber deteriorates.
If you have read this and think I have left something out, or make a mistake, please let me know so I can add to or make changes.