1. It plays the role of tracking mark when flying at night, increasing the fun of using at night; 2. The red and blue colors alternate, and the brightness is bright; 3. Small weight, light volume, almost no impact on flight, can be placed at the bottom of the arm or the position of the nose; 4. Non-destructive installation, additional 4 batteries and 4 foams when shipped, long battery life Of fun. 5. Net weight: 6g 6. Size: 1.3x1x1cm 7. Battery capacity: 35mAh/pc