Assorted Large Drilled Ball Set, set of 12, A 3mm hole is drilled through the center of each ball. Every set comes in a convenient plastic storage case, with a foam bottom that holds each ball firmly in place
Resonance Tube Apparatus, Long version, Material: Acrylic, Mounted on retort stand with clamp and boss, with metal vessel, connecting tubing and spring clip supported on iron ring, Dimension: 120cm