Replacement Pith Balls for Electroscope, 10-Pack Item Type_Net Hand-cranked friction-wheel drive sandwiched between

Hand-cranked friction-wheel drive sandwiched between clear acrylic plates

Aluminum 40cm precision force table with tapped pulley positions and central ring assembly for resolving and composing force vectors under equilibrium conditions

one fitted with an exploder piston for momentum and action-reaction investigations

Life-size digestive system model in two parts reveals the esophagus-to-rectum path with stomach

this seven-piece set traces fetal delivery from engagement through crowning to placental separation for labor and delivery teaching

Replacement Pith Balls for Electroscope, 10-Pack Item Type_Net Hand-cranked friction-wheel drive sandwiched betweenSpare pack of ten low mass pith balls sized for the standard pith ball electroscope, supplying replacements when the originals lose loft or split during repeated charging cycles.