I went to a junkyard today to get a new speed sensor for my 94 civic and the dude gave me this and told me it was the sensor... is this correct because it doesn't look like the sensor I have in there now.

 

whoops i didn't mean to post in this forum.

 

Yes, that is a speed sensor. The half with the gear slides into the transmission and is turned by a 'speedo gear' on the differential, generating a voltage that your speedometer displays with a needle.

Now whether that's the correct one for your car, I couldn't tell ya.