Battery Powered Acceleration Timer
This battery-powered timer produces 30 to 50 marks per second for dynamic experiments. 1.5V motor operates on two D-cell batteries (not included). Wooden base improves stability, reduces vibration and permits attachment to a ring stand post. Striker mechanism acts against an aluminum plate to produce improved-dot definition on the ticker tape.
43mm disc carbon (12) and small tape roll 15mm width x 30mtr.