US$ 13.99
Red LED on a demonstration base with 4mm plug connections
Ten-pack of 16mm steel ball bearings sized as a larger projectile for ramp experiments
and torsional balance
Two-position copper plug key switch with 4mm terminals and two removable plugs
Ticker Tape Timer Device with Carbon Disks Physics Red LED on a demonstrationPlastic cased ticker tape timer at 4. 5 by 3 by 1. 5 inches producing 50 60 dots per second via a vibrating striker, shipped with ticker tape, carbon discs, and a movable disc plug.