Wall wash led strip channel for Upward Architectural Lighting, which is made of 6063-t5 aluminum alloy material and with white powder-coated surface treatment, better heat dissipation and anti-oxidation features, has a longer lifespan than other similar products. the standard length is 2m or any size for your project, the inner width is 18.7mm and compatible with double rows Flexible LED Strips, there is one type of diffuser available, the PC opal matte diffuser, which made of brand stable material, anti-yellowing, perfect light distribution and high light output. the LED Strip Diffuser Tube with upward indirect light design for architectural, can be recessed in the ceiling drywall or wall plaster-in, the end caps with wire hole included. there are L and Straight shape connectors optional, you could connect the LED Diffuser Tube together.