2 LBS Natural Leca Clay Pebbles for Plants- 4-16mm Expanded Clay Leca Balls for Indoor Plants, Hydroton Clay Pebbles for Plants Hydroponic & Aquaponics Growing, Orchids, Drainage, Terrarium. 100% Natural and PH Neutra: Our expanded clay balls for plants are made from natural clay and fired at high temperatures to form strong, round leca balls!