UPuper Hydroponic Greenhouse Systems Starter Plugs: Premium rock wool clone cubes designed for precision seedling cultivation. High-density rock wool ensures optimal water retention and air circulation for rapid root development. Sterile, pH-neutral material prevents disease and promotes healthy plant growth. Ideal for hydroponic systems, greenhouse propagation, and indoor gardening. Engineered with uniform cell structure for consistent moisture distribution and maximum germination success. Perfect for commercial growers and hobbyists seeking professional-grade starter solutions. Bulk pricing available for large-scale agricultural operations.