30 Growing Sponges for General Root Growth, for Vegetable Cuttings and Seedlings. Description: Hydroponic. Ideal for growing vegetables without soil, promoting root development in hydroponic systems. Material. Made of premium peat and coconut fiber, providing good water retention and aeration for seedlings. Expandable. The blocks expand after soaking, increasing in size to accommodate growing roots and promote robust plant growth. Convenient Size: Compact design with dimensions before soaking of 2 cm/0.79 inches (top diameter), 2.5 cm/0.98 inches (bottom diameter), and 3.2 cm/1.26 inches (height); expands to 2.3 cm/0.91 inches, 3.5 cm/1.38 inches, and 3.8 cm/1.50 inches respectively after soaking. Package includes a set of 30 growing blocks, ideal for starting multiple plants at once in home or commercial settings. Specification: Size Chart: Before soaking: Top diameter 2 cm/0.79 in, bottom diameter 2.5 cm/0.98 in, height 3.2 cm/1.26 in. After soaking: Top diameter 2.3 cm/0.91 in, bottom diameter 3.5 cm/1.38 in, height 3.8 cm/1.50 in. Package includes: 30 growing sponges. Note: Please allow for slight errors due to manual measurement and different monitors.