Air dry clay. Strictly Complies with the ASTM F963 and ASTM D4236 Standards and Requirements. Clay are stored in transparent plastic sealed bags which helps it to avoid too dry to affect the use. After first-time use, please use the ziplock bags to preserve the clay so that you can feel free to use as many time as you like. Great air dry clay for slime.3. Perfect gift for kids at Children’s Day, Christmas, birthdays or other anniversaries. DIY essential hand-make craft play toy for parent-child interactive activities at school and home. Great toy full of joy for children over 3 years old and adults. They'll enjoy the sculpting modelling clay making accessories all day while engaging in fun, sensory play; Great activity on daily days, play-dates, birthday parties, parent-child interaction, etc.4. Imagination and Creativity: Perfect Early Childhood Education DIY toys for kids( Over 3 Years Old). Boost your children’s creativity and emotion development; develop fine motor skills at intellectual development, crawling ability, manual brain skills, grasping ability; Enhance sensory development and hand-eye coordination.5. Recommend for ages 3 and up to use. Fully sealed shelf life is 12 Months. If there is any question about the product, please feel free to contact us. Our motto is that we always take responsibility to provide the best service to satisfy customers.