This is the Marking Guide with Fin Attachment Guide from Estes®. Suitable for Ages 10 & Older with Adult Supervision for Those Under 12. FEATURES: Easy way to mark fin and launch lug placement lines Fin gluing jig included Mark reference lines down or around any body tube REQUIRES: Hobby knife (RMXR6909) Pencil INCLUDES: 1 tube marking guide 2 fin marking tools for most Estes body tubes COMMENTS: Due to small parts that could cause a choking hazard please keep away from children 3 years of age and younger For your safety and enjoyment, always follow the NAR Model Rocketry Safety Code while participating in any model rocketry activities oct6/95sk updated tlc 1/10/13