Features: 1. Stone Sample Collection: The rocks in different types are well polished and packing with box. Also a great way to introduce children to the joys of rock collecting! 2. Bring Kids Knowledge: Rock and mineral collecting is a popular hobby and this rock collection kit is the perfect way to inspire a lasting love of geology for kids 3. 24 Days Surprise: Complete 24 challenges to raise festival expectations. Each cell contains a different rock waiting for being discovered. 4. Wide Applications: Perfect gift for collection and friends. Have them in your living room bedroom office or even bag. 5. Note: Each natural stone is natural and unique. The color and texture of actual stone may show slightly differences to the images. Notice: Actual color may be slightly different from the image due to different monitor and light effect. Please allow 1-3cm deviation due to manual measurement. Description: Material: rock Size: As the picture shown Battery: no Color/Style: As the picture shown includes: 1 set of Advent Calendar "