Dear customer, Thank you for choosing our products. If there is any problem with our products, please contact us through the order information. We will be happy to serve you and solve it for you as soon as possible within 12 hours, thank you! Made of ABS material,can be reused without crumbling.Not easy to be deformed and corrosion resistant. Many holes in the bottom and side of these cups,make fertilizer permeate into the soil slowly,which won't burn the plants roots easily. to use the fertilizer box,Just inject fertilizer directly into the plant soil of the bonsai.Then water the plants and the fertilizer will dissolve the nutrients into the plants. MULTI-PURPOSE:Perfect for bonsai,succulent,flower,orchid and small plant.Great accessories for indoor plants and lawn garden growing. REUSABLE AND DURABLE:The fertilizer box can be used repeatedly and durable for long time use.