The Sun System 150 W HPS grow light is very compact because the ballast is built into the unit. These are great for small cabinet or locker grows because of their compact size.
Sun System 150 W HPS Grow Light A Versatile Reflector
I have 2 of these and love them because they are so portable you can hang them almost anywhere.
I use mine for side lighting, starting seeds or rooting cuttings.
They don’t give off to much heat and replacement bulbs are cheap.
A great way to get started growing and yields are much better than using CFLs.