What manufacturer? What model? Is it line voltage or low voltage? Florescent or incandescent? Electronic or resistive?

Manufacturer is Leviton. It didn't come with any packaging so I'm not sure voltage, model or type it is.

I took the cover off it and got the info.
Sureslide 6633-p
120 v
Incandescent

What you have is a 3-way dimmer switch. The wiring diagrams are available on-line if you do a search. The green wire goes to ground, and the black to the hot supply. If you're using this in a 3-way mode, the two reds to go the other 3-way switch. In a single switch mode, one of the reds goes to the fixture, and the other red should be capped off and not connected to anything.

Thanks for the info. Hopefully I can hook it up tomorrow.

Below is a link to the PDF of the instructions from Leviton's site

Here is a link that might be useful: instructions