Machined from solid aluminum, this unique tooling consists of a ram and heavy wall aluminum case reinforcing sleeve. Simply glue a plug into one end of a 3/8" ID X 2" long tube (Stock #T38M or #T38M12 - 3/8" ID X 12" or 24" long, cut into 2" lengths and 3/8" paper plugs) place it in the mold sleeve, add whistle mix and compress with the ram until tube is 75% full. Comes with diagramed instructions featuring three power rated whistle formulae, and tube sample. Tubes and chemicals not included (Potassium or Sodium Benzoate and Potassium Perchlorate).