With your Kromski loom you will find an 8dpi heddle included. You'll be able to use double knitting yarn in this heddle but if you'd like use different gauges of yarn you'll need a different heddle.
Kromski Loom Heddles come in four sizes, 5, 8, 10 and 12dpi so you can weave really chunky yarn on your 5dpi heddle (maybe you'll be weaving a rug) right through to fine yarn on your 12dpi heddle.
If you want to weave double the width of your loom you will need two heddles of the same size.
To see scarves woven by complete beginners using Kromski looms, check out our instagram page