Tube into fuel tank or airbox? What is it?

I'm new to bikes, and just found a pic of a '93 ZX-7R with a tube going into the fuel tank area. No others ZX-7Rs I have seen have got this so it must be a mod, but what is it, and what does it do? Please see picture. I think I've seen it on other bikes in the past, but don't know what it is.  

Ok, so I'm a dumbass. Having looked at it again, I can see it's from the air intake next to the screen, but why the new fairing with high level air intake? Other bikes have the air intake on the other side leading into the frame.  

That is stock for that bike. They are ram air tubes. Feeds air straight to the air box under the tank. It doesn’t actually go into the fuel tank, but through it. Most modern sport bikes have ram air, but the tubes are hidden in the body work. In case you don’t know how ram air works; basically by using the bikes forward motion to “ram” air into the air box it raises the air pressure in the air box. More air means more fuel, more fuel and air mean more power.  

Ah, gotcha. Thanks. Yeah, I've heard of ram-air, and having looked again at those pics, I was looking at ZX-7's and ZXR-750's on bikepics in the ZX-7R section. Other ZX-7Rs do have it. Doesn't look too pretty though.  

Sorry, we replied at the same time. To answer the second question, that was just one of the first attempts at ram air, they fine tuned it later. The Darth Vader tubes were only on the '93 model I think. The bike in the pic is awsome condition BTW. That's a bike I wouldn't mind gettting my hands on. A modern classic, also know as a "snorkel ZX7"  

Actually that came from Kawasaki on the ZX-7 from 1990 or 1991-1993, I just loved those old ZX-7 & ZX-7R'S. They are one of my favorite all time bikes, they were SOOOOO uncomfortable!!!!  

Also, FYI, that version wasn't actually a ram-air system. The snorkels basically led down to the airbox area under the tank, but didn't connect to the airbox itself.
That ZX-7R is a '90-'92 generation; I believe the '93s had the first actual ram-air system, with the big duct running on the right side into the frame spar and directly into the airbox.