This nozzle is printed to fit on a 40mm pipe. It turns your simple pool into a fountain :)Depending on the power of the pool pump you might need to increase or decrease the opening of the nozzle. Only slightly smaller nozzles will be ripped to pieces when i try them with our pool.I printed them using no infill or solid layers and 4 perimeters with a 0.5 Nozzle at 0.3 mm layer height.