The Gill cast iron shot put is a great option for beginning shot put players looking for their first shot. The 6lb weight is certified for youth players 9-12 years old and girls ages 13-14. The 4k (8.8lb) weight is certified for girls' high school (NFHS) play and women's NCAA and World Athletics competitions. The 12lb weight is certified for boys' high school competition. The 16lb weight is certified for men's NCAA and World Athletics events.