Just add water and watch the Water Marbles grow in size! They come in a variety of colours and once grown, you can keep your Water Marbles in an airtight container for weeks or they can be rehydrated once they are dehydrated!
Please note that this contains small parts and therefore, should be kept out of the reach of children under 4. The marbles present a choking hazard and should not be consumed. Please supervise use at all times.