Features: Made of high-quality rock wool material, it is soft, durable, breathable, reusable and waterproof, ensuring factory safety. Easy to use, super volume water absorption and water retention capacity can reduce irrigation frequency or quantity, reduce water and fertilizer consumption, and effectively reduce irrigation costs; rock wool matrix has no impurities and no germs, which is conducive to the recycling of water and fertilizers, improving the utilization rate of water and fertilizers, and operating The PH value of the matrix after soaking in the nutrient solution is stable. In the greenhouse without water and fertilizer circulation system, the utilization rate of water and fertilizer can be increased by more than 60% and 25% respectively, and in the greenhouse with water and fertilizer circulation system, the utilization rate of water and fertilizer can be increased by more than 75% and 78% respectively. Versatile and ideal for sprouting hydroponic plants such as DIY nursery boxes. Whether you use a commercial cloning machine or a dedicated nursery box, this is the right choice for plant germination. Specification: Material: rock wool Size: as picture shown Color: as picture shown Package Includes: 20/25/28pcs Notes: Please allow small errors due to manual measurements. Different monitors may display slightly different colors.