This design is a rain water collector for 65 mm square PVC downpipes commonly found in the UK and Ireland (EN 12200). The collector can sit closer to the wall if you have downpipes with small gaps behind them.
The main body of the design prints in two parts without support and the there is a alignment feature to help bond the parts together.
I printed the parts in PLA+ as to test the material in exposure over the next year or two. It is probably recommend to use PETG, ABS or ASA if you have harsher weather than we get in Ireland!
This collector is designed to use the union nut and hose adaptors in the Rain Collector by Patrick Harrer that uses a M40 x 3 nut to allow modular connection types.
The author remixed this model.