Proximity sensors, read with Arduino?

Hi
I need to read some form of proximity sensor and found one at ebay but it has an Whopping 320KHz TTL npn puls as output. Is it possible to read that high frequency with Arduino?

is it one puls or a continuous stream?
A link to a datasheet would be nice
A link to the ebay site would too be helpfull

First word that came up in my mind was "interrupt"

This is the facts taken from Ebay. They didnt have any datasheet. Interupt can read signals like this I know but my question was if the Arduino can read so fast pulses as 320KHz or is it that the sensor can read as fast as 320KHz pulses before read error?

Features :
100% Brand New
This hall sensor is determined by the voltage regulator, Hall-voltage generator, differential amplifier, Schmitt trigger, and a collector of output is composed of magnetic sensors, enter it as the magnetic flux density, output is a digital signal.

Characteristics:

Wide supply voltage range
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High frequency
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Long life, small size, easy to install
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Direct and TTL.MOS and transistor logic circuit interface

Product Details:

Model: NJK-5002C
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Appearance: M12mm cylinders
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Output type: NPN 3-wires normally open
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Detection range: 10MM
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Power supply voltage: 6-36VDC
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Output current: 200mA
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Detected objects: magnet
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Switching frequency: 320KHZ
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Shell material: copper

Package
100% Brand New
Hall Effect Hall sensor Proximity Switch NPN 3-wires normally open+ magnet x 1