Check the listing for details. GeoCentral Tortoise Hatch 'Ems Egg Toy. Condition: New. Listed at 6.99 USD. GeoCentral Tortoise Hatch 'Ems Egg Toy Just completely submerge your 2.5 inch turtle egg in a glass or bowl of water, and wait. Within 12-24hrs, cracks will start to appear in the shell of the egg. And within 48 hrs, you will have hatched your very own baby tortoise. Leave it in the water, and it will continue to grow! Once you take it out of the water though, after a few days it will start to shrink back down to its original size. Just put it back in the water, and it will start to grow again! Tortoise colors may vary Growing animals and other things (brains etc!) that are made to increase in size in water are made up of two polymers. One is poly(vinyl acetate) which keeps the original proportions and shape of the item or creature, and the other polymer is polyacrylamide which is the super absorbent polymer. The growing creatures have many teaching applications in science and math, including graphing, drawing conclusions, and measurement using linear, mass and volume. The Growing Creatures Book by Anne Linehan and Betsy Franco details measurement and data collection projects integrating math and science. Recommended for ages 6 and up Product Details BrandGeoCentralColorIvoryManufacturerGeoCentralProduct TypeScience KitsMpnHETE Submerge the egg in cool water and watch!In 48 to 72 hours and keeps growing to 5 inches in lengthGreat way to teach measurement!Beginning egg measures approx 2.5 inches Check out my other items.