This stitch can be done using any size yarn and hook. For this pattern I used worsted weight yarn 4 ply for the US and 10 ply for AU and a 5mm / H hook.

Ch = chain

sk 2 sts = Skip Two Stitches

sc = single crochet

TRC = Triple Crochet

DC = Double Crochet

FPDC = Front Post Double Crochet

BPDC = Back Post Double Crochet