From OnBuy
GARDENA Premium Water Stop, 13 mm (1/2") - 15 mm (5/8"): Water stop, frost-resistant, packaged (18253-20)
Conrad Electronic
GARDENA 18255-50 18255-50 Hose connector 13 mm (1/2) - 15 mm (5/8)
This product is also available at 2 unverified stores.