A needle for tatting. Each package contains a single tatting needle. The needles in sizes 0-0, 1-0 and 2-0 are best used for yarns like you would use in knitting. The needles in sizes 3-0, 5-0, 7 and 8 are best used for cordonnets or finer cotton threads as used in crochet/embroidery or specifically for tatting.
Use 0-0 for chunky weight yarn.
Use 1-0 for worsted weight yarn.
Use 2-0 for DK and finer yarn
Use 3-0 for Perle cotton #3/size
Use 5-0 for Perle cotton #5/size 10-20 cordonnet
Use #7 for size 8-50 (fine) cottons/size 20-50 cordonnet
Use #8 for size 50-100 (very fine) cottons/size 50-100 cordonnet