Use these 2-7/8" inside-diameter cardboard tubes to build bottle rockets from scratch!
Each tube is 6-1/2" long and may be joined to make longer tubes (instructions included). Tubes will fit over most 20-ounce plastic bottles (use our Bottle Block for the engine section), or they can be glued to 2-liter bottles.
Use these 2-7/8" inside-diameter cardboard tubes to build bottle rockets from scratch!
Each tube is 6-1/2" long and may be joined...
