Related Clues:

• It picks up readings
• Gillette brand
• Electric eye, e.g.
• Detecting device
• Gillette razor brand
• Probe's kin
• Security system part
• Motion detector
• Motion detector, e.g.
• Polygraph component
• Gauge of heat or light, e.g.
• Electric eye, for one
• Security device
• Detection device
• Security system component