The Philip Harris Foundation Physics - Light Gate includes a battery operated timer, two light gates with cords, 9V battery, a backup AC adaptor, and a user manual.

The system is perfect for experiments on the go.

The light gates come with convenient thumbscrews, making them easy to connect to the Foundation Physics Universal Stand (not included) and reposition.  

• Standard Stopwatch Mode: records time from start to stop
• Interval Mode: measures the duration of an interruption 
• Frequency Mode:  tracks the rate of regular interruptions
• Period Mode: calculates the time between the first and third interruptions
• Count Mode: records the number of times the photogate beam is broken and it also functions as a 
• Dimensions: 15 x 15 x 6 cm.