"Colbyt" in
news:0%Byf.490595$084.379544@attbi_s22:

2-4 toggle bolts 1/8" size will hold it just fine.

my recent experience:
tenants will tear it out if the fixture is hung from the box plus two large toggles (thru the
sheetrock). the toggles leave large holes in the sheetrock.

i'm going to mount the next fixture using the box plus two of the retrofit adjustable-bar
hangers
http://castlewholesalers.com/products/2278920.jpg