Board Thread:Questions and Answers/@comment-8379598-20130705013513/@comment-8540798-20130705070154

The sensor peripheral is the item you place directly next to your pc, which has a slot in it's gui for a single sensor card. Depending on the sensor card you use, you can do more things on the pc, like detect inventory levels of nearby chests, make a map of nearby mobs on the monitors etc.