These 50pcs rockwool blocks are great for rooting cuttings, starting seeds, plant propagation, and hydroponics. Made from molten rock spun into cotton candy-like fibers, they encourage faster initial rooting and are much easier to use than soil. The predrilled planting holes make seeding and plant propagation a breeze, and their high water absorption while retaining oxygen is perfect for establishing a root system. Ideal for hobby and commercial growers alike. Features 1. Made from molten rock spun into cotton candy-like fibers and then compressed into cubes, blocks, or slabs. 2. Great for rooting cuttings clone plants, germination start seeds and more. Encourages faster initial rooting & its firmness is guaranteed. 3. Much easier than starting in soil! Predrilled planting holes make seeding and plant propagation a breeze. Great for hobby and commecial growers. 4. These rockwool starter plugs are widely used in hydroponic, seed starting, cuttings, plant propagation and so on. 5. Rockwool grow cubes keep the seeds long enough to establish a root system because of they have high water absorption while retain a lot of oxygen, cubes will not sepreate after immersion, easily transplant to net pots, soil, planting machine after rootted. Specification Material: Rock Wool Color: Green Size: 444cm / 1.61.61.6in Weight: 240g Package Include: 50 Rock Wool Blocks