Fitbit, which helped pioneer this kind of wearable tech, is also back with Flex, which distinguishes itself by letting users swap its sensor unit from one wristband to another to co-ordinate with their clothes.

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Packed in their 7-by-2-foot titanium-framed fiberglass bodies are terabytes of cellphone flash storage, a dual-core ARM processor running open Linux software, a battery pack, sensor arrays, a GPS unit, and wireless and satellite communications systems.

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As far as internals go, the unit features a 16.1 megapixel APS-C sensor (like last year), boasting a top ISO of 16, 000 and new Bionz image processor.

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If a sensor detects a problem, the RFID tag transmits this to the control unit which can emit an (audible) alarm or shut off the water supply.

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Each contains a unit of the system, such as a microprocessor and memory, plus sensor or radio transmitter.

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