Lang Yarns Cashmere Light knitting yarn is composed of cashmere wool blended with nylon for strength and knits on knitting needles 5.5-6 mm for a gauge of 20 and 31 rows.
A 25g ball contains about 85 m (92 yd) so for quantities of yarn plan on:
450g = 18 balls for men size M
375g = 15 balls for women size M
200g = 8 balls for children 10 yrs
Hand wash with detergent for wool without fabric softener.