Hard Hats is an insert set in 2003 Leaf. This 12-card set features some of baseball’s best hitters. A picture of the player is superimposed over the player’s batting helmet. The set is very similar to the Hard Hats insert set in 1997 Studio. The cards were inserted 1:13 packs. The set is paralleled by a game used set featuring chips of batting helmets embedded on the card. There are very few batting helmet cards in the hobby thus the cards are highly valued despite being serial numbered to 100 copies each.