Hydroponic Sponges are used to grow plants such as fruits, beans, vegetables, flowers and so on in shed planting, modern agriculture, etc. Color: White; Material: Sponge; Total Size: 40 x 30mm / 1.57 x 1.18"(D*H); Package Content: 50pcs x Hydroponic Sponges Root-fixing sponge, good elasticity and strong water absorption, easy to install, edge opening design for better installation. Steps: 1. Before using the sponge, please making the sponge wet with the clean water. 2.Place the plant in the center of the sponge. Please allow 1-2mm differences due to manual measurement.