Nozzle 'Schaumsprudler' 22-5 K
 
It's a great addition to any garden pond, water feature or water display. This foaming jet nozzle creates a vertical jet of water that is about 20mm (¾") in diameter. The nozzle is designed to mix air into the water stream, creating a foaming sound that adds to the overall ambience of your outdoor space. It comes with a ½" BSP male screw thread for easy installation.
 
Nozzle 'Schaumsprudler' 35-10 E.
 
This nozzle is designed to create a foaming jet of water that's perfect for garden ponds, water features, and water displays. The foaming sound is created by mixing air into the water, and the resulting vertical jet of water is approximately 32mm (1¼") in diameter. It comes with a 1" BSP male screw thread, making it easy to install.

Schaumsprudler 55-15e fountainhead.
 
It seems to have some impressive features such as creating a vertical foaming jet of water, with air mixed into the water to produce a soft foaming sound. It is made from a durable polished Stainless Steel & Tombac construction, making it ideal for larger garden ponds and water displays. The fountainhead has a 1½" BSP male screw thread.