Blast off with the Puma Rocket Estes model rockets range from "ready-to-fly" in just minutes, to kits that provide many enjoyable hours of building fun. Estes kits are classified into five categories. READY TO FLY (RTF) No paint, glue or modeling skills required. Rocket comes assembled and is ready for liftoff in just minutes. E2X No paint or special tools needed. E2X kits contain parts that are colored and easy to assemble. Simply glue the parts together as per the instructions, apply the self-adhesive decals, attach the recovery system and you are ready to blast off! Assembly takes 1 hour or less. SKILL LEVEL 1 Requires some painting, gluing and sanding. Features laser-cut balsa fins, slotted body tubes, plastic nose cones and self-adhesive decals. Step by step instructions make building very easy. Assembly takes at least an afternoon. SKILL LEVEL 2 First tier of more advanced kits. Requires beginner skills in model rocket construction and finishing. Features laser-cut balsa or plastic fins, plastic nose cones and unfinished body tubes. Assembly may take a complete day. SKILL LEVEL 3 Second tier of more advanced kits. Requires moderate skills in model rocket construction and finishing. Features multiple laser-cut balsa fins and parts, unfinished body tubes, complex designs and plastic nose cones. Assembly may take a couple of days.