Come and see our amazing products. The hourglass timer 30 minute can help your child do things, study more effectively, and enhance the sense of time. Hourglass half hour minute timer can be used for cooking, games, classroom, study, desk, office decoration.This 30 minute hourglass timer is mainly used for entertainment, not an accurate timing device, so there is a time deviation. However, 30 minutes has reached the industry standard of+-10% of the highest quality in the United States. Pls confirm with us about the packing info, stock color and exact production time before placing your order.