Monarch Pure Copper Bamboo Rain Chain, 8-1/2-Feet Length Cup Per Chain: 17 Cups Cup Size: 4"(L) x 4"(W) x 2.25"(H) Each cup has a wide receptacle to capture most of the rain water and efficiently transports it to the next cup and so on till it reaches the bottom of the rain chain where the rain water can be collected in a barrel or receptacle for further reuse. Over time the pure copper rain chain reacts with the oxygen in the air and develops a beautiful brownish patina on the surface. Some splashing will occur and is a natural occurrence of all rain chains.