Hydroponics Seed Growing Media Sponges is a good seed starter. Perfect for starting new plants from seed or hydroponics. | Sponges Size: 1pc whole sponge which have 100pcs small sponges.Each small Sponges size is about 25*25*25mm.You also can separate them to use. They fit for the 1.8" net cup pots baskets. | Package included:1pc whole sponge which have 100pcs small sponges. They can fit for most seeds, such as fruits, beans, vegetables, cereals, flowers and so on. | Made of environmentally friendly and non-toxic material,Their color is ivory white but when they touch the air, the color may become the light yellow. This case is normal. It won't influence the using of the sponge. Please don't worry. | Great equipment for Soilless cultivation,easy to use. Perfect for indoor garden Hydroponic plants and planting vegetables.