Designed for use with the Nerf Rebelle Agent Bow Blaster (sold separately) these message dart refills are essential for any secret mission. Use the special pen to write your message and conceal them until its time to fire. Give the decoder to friends so they can decipher the message; Arrow refill pack includes 3 arrows. Arrows whistle as they fly. Arrows fly up to 85 feet when fired from the Agent Bow blaster (sold separately). Size H34.2, W15.8, D3.8cm. (not included) plus (not included). For ages 8 years and over. WARNING(S): Not suitable for children under 3 years old. Only for domestic use.