These super durable EPO foam planes are powered by a small LiPo battery which provides many flights on a single charge. A built in 15 second timer keeps the model from flying away or overdischarging. You will need nose weight to get these to fly correctly. We found that 5-8g of lead was necessary. Also some dihedral can be bent into the wings very easily to get the necessary spiral stability. The result is a very consistent flying model that is great for small fields and young children.