Quartz Gravel #4, 1/8 X 1/16 Packaged in Half CF Bags
NSF 61 Approved Support Gravel. One cubic foot packaged in 1/2 cubic foot bags.
Support gravel, the lower strata of a filter bed, acts to support other filter layers. NSF 61 Approved for use in potable water systems.
Minimum quantity of 4.