The Gill brass shot put is an incredibly durable shot built to last for many seasons. This durability is due to the top-quality brass construction that is machine-turned for precision and shape providing an unmatched design and feel. This brass shot put is very balanced, and won't chip or lose weight throughout a long season. The 4k 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.