I AM a sweatshirt with butterfly sleeves. My long cuffs helps create the volume at the bottom of the sleeves. I have 3 snap fasteners on the left shoulder to open and close. All seam allowances are included in the pattern. The pattern is enclosed in an envelope. It contains the sewing pattern along with a step by step illustrated explanation guide. The different pieces overlap with each other so you will need to trace the pattern on paper.