help with ballast id

So Im out strolin stoned this morning in a junk yard and I see this big light ballast laying in the back of a pickup. On the plate It reads ballast HPS, watt 475. My question is how bis of a bulb will this handel? I dont want to buy the wrong size bulb you know.Oh ya the best part I talked with the yard manager and bought it for 20 bucks Even if it doesnt work I could probly fix it with new parts cheaper right? Any itellect would be greatly apretiated.

I is good for a 475 watt bulb

If you know what your doing, then yeah, you should be able to fix it quite easily.

Sweet thanks for the info.