Lang Yarns Merino 400 Lace knitting yarn is composed of 100% fine wool and knits on knitting needles 2.5 and 3.5 mm (US -4) for a gauge of 32 stitches and 42 rows.
There are about 200 meters (218 yd) in a 25 gram (0.88 oz) ball so plan on:
400g = 16 balls for Men size M
300g = 12 balls for Women size M
200g = 8 balls for Children 10 yrs.
Machine washable at 30°C (86°F) with detergent for wool without softener, iron at low temperature.