Rehau couplings.
Plastics-compatible brass system.
For ½" garden hoses.

These brass couplings offer a robust and weatherproof alternative to the ubiquitous, standardised, plastic, garden hose coupling systems. Fittings from Gardena® and other manufacturers are compatible with this coupling system for ½" garden hoses (maximum outer diameter 18.7 mm; maximum wall thickness 3 mm). You can connect the brass couplings at any given place in the system to the plastic couplings you may already have at home.