Description from the book “Impossibly skinny gloves stretch to fit. Change sizes by increasing yarn weight category and needle size for a Small/Medium, one more to fit a size Medium/Large.”

For larger sizes To fit size Small/Medium (7”-7.5”/18-19cm) use medium weight (3) yarn and size 3 (3mm) needles. To fit size Medium/Large (7.5”-8”/19-20cm) use medium-heavy weight (4) yarn and size 4 (3.5mm) needles.