An intake replaces the stock air filter... A stock air filter is usually a compacted material that takes particles out of the air. The material is so compact that it actually restricts the air flow to the engine. Air+Fuel+Spark=Horsepower... increasing any of the three will slightly increase the need for the other two and increase the horsepower. Essentially what the Air intake does is replaces the the compact air filter with a less restricive filter... it will still catch the same particles it just allows more flow of air. The metal tube is there to "cool" the air. Cold air is less dense than hot air... therefor you can pack more into a combustion chamber which increases the force of the combustion which increases the angular velocity of the force on the crankshaft (my bad... went into engineering mode)... in short: the colder the air... the more oxygen there is to combust... the bigger the combustion... the more horsepower.

And despite popular belief... you can buy air intakes that have persperation valves that bleed out any water that gets by the filter... so you can drive it in wet weather and its not going to hurt the engine. Don't buy the cheapest one that you can find because there is a difference... A cheaper one won't have a quality filter that will give your engine maximum protection from particules and waterlock (hydrolock)... a cheaper one also won't cool the air like as well as its suppose to. A high-end intake has a ceramic coating on the inside of the intake. This ceramic coating is more stable at high temps and helps cool the air better than the a stock aluminum intake shaft.... But yeah, theres no button to turn it off. Its just a part that you put on the car to replace a stock part... but its not hard to take off if you don't like the results. You shouldnt have to worry about hydrolock if its raining... but if there is a lot of standing water and you opt for a cheaper intake you might want to take caution. looks good though man... good luck with that.