need help with halides

[ashchad]

hi i just got into halides for my reef tank, and i bought some light bulbs and housings, they are 150 w bulbs and housings.....now the problem that i have is they won't plug into the wall, they have this piece of plastic on the end some one said that i might need a ballast.
if i do what do i need?
here are some pictures, any help would be awesome

[ccCapt]

You just have the pendant. You need a ballast to plug the pendant into. The ballast gets plugged into the wall.
PFO 150 Watt Single Metal Halide Ballast