The hardware is cheap and small, so a radio can fit into a ring-size device.

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Soon, rows of tables outside the church are enveloped by youngsters offering their personal details, including the size of their ring finger.

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The infra-red radiation emitted by the dust can also be used to measure the size of the ring directly, and this has been done using the Keck telescope on Mauna Kea, Hawaii.

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Just a few millionths of a millimetre in size, the minute machine resembles a ring threaded on a rod.

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Yet scientists are already speculating that this planet may be of a similar size to Jupiter and have its own ring system.

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The large size of the key (sorry to go on about it), the ergonomic turning head and chunky ring, are all designed to be easier for people with physical impairments to get it out of a bag and in to the lock.

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