Plastic Crochet Hook Size H for Small to Medium size; Size I for Medium to Large size OR ANY SIZE HOOK WHICH WILL RESULT IN STITCH GAUGE BELOW.
GAUGE:
Size H hook; 5 ch sts = 1 inch;
Size I hook; 4 ch sts = 1 inch
MEASUREMENTS:
Width across back at underarm:
17 (19) inches.
Width across each front at underarm:
8½ (9½) inches.