This is a roll-brim baby hat in for preemie sizes: Large (nearly full-term), medium, small, and micro. Gauge isn’t critical if you plan to make many hats in different sizes. Before making hats for your local NICU, be sure to call first! Ask about fiber requirements. Some want NO acrylic, some want ONLY acrylic, and some aren’t concerned about fiber so long as it is washable.