The vest is without seams made of more modules knitted in diagonal direction. That gives the knitting a more flexible shape and makes it fit nicely. The pattern is in 3 sizes: Chest measurement 86 – 96 – 106 cm. It is quite easy to change the size. If you want the vest wider or narrower you can increase more or less stitches in the triangle in the beginning of the vest. If you want the vest longer or shorter you can change the number of rows between the in-/ decreases in the side part.
If you are knitting on a long circular needle you may measure on your body or on a sweater you know is fitting during the knitting.