Features: This 4 pack drainage kit is designed for use with concrete timber and natural stone retaining walls. It provides dependable water management for landscape walls flower bed walls and courtyard walls. The simple installation helps support stable wall structure and consistent performance in outdoor environments. A drainage solution for retaining walls between 3 and 8 inches in size. Each set comes with four drainage pipes to direct water away from wall structures. The reliable design works well in outdoor conditions and helps maintain steady wall condition over extended use. Specifications: Material: plastic, aluminum Color: silver, black Size: suitable for 3-8 inch wall materials Package includes: 4 x Retaining wall drainage blocks Notes: Manual measurement, please allow slight errors on size. The color may exist a slight difference due to different screen displays