With this hands-on craft kit, students learn basic STEM elements, specifically the principles of gravity and engineering, and engage their artistic sides. First, students construct their cups and use the stems to create hooks with the bobbins. Next, they race the baskets down the zipline! For a more in-depth examination of gravity, add weights to the baskets to see how the added weight affects the baskets going down the zipline. Includes 3 1/4" 9 oz. paper cups; 12" chenille stems; 3/4" diam. plastic bobbins. String not included. Makes 10. All craft kit pieces are pre-packaged for individual use. Kits include instructions. Simple assembly required. © OTCThe following item is considered a STEAM craft. The directions for this item are extremely simplified, as there is no right/wrong way to put this item together. The purpose of this product is to learn through the process of experimentation, and trial and error.