Rockwool Grow Cubes (Mm 40/40) 45 Cube Sheet 1.5 in X 1.5 in X 1.5 In These are individually wrapped small cubes for seeds and cuttings Rockwool cubes guide roots downward You can set them on top of other rockwool cubes, slabs or other growing media Sold in sheets of 45 cubes Measure MM 40 / 40 1.5 x 1.5 x 1.5 inches