Lang Yarns Merino 150 knitting yarn is composed of 100% fine merino wool, knits on knitting needles 3-3.5 mm (US 3-4 / UK 10-9) for a gauge of 27 st. and 37 rows.
There are about 150 m (164 yds) in a 50 g (1.75 oz) ball so plan on:
650g = 13 balls for Men size M
500g = 10 balls for Women size M
400g = 8 balls for Children 10 yrs
Machine washable at 30°C (86°F) with detergent for delicate wash without fabric softener.