Old Zinc Flower Pot, 0.34 L - Small Old zinc flowerpot 9 cm. Volume: 0,3 L (0.5 UK pint). The flower pot has a small hole in the bottom and a rubber plug to close it if required.. Using zinc in the garden is an ancient tradition and is used in many different ways. A classic round flower pot that can hold all sorts of plants. It is specifically designed for a 9 cm (3.5") size pot. Switch between a drainage hole or a closed bottom at a whim with the rubber plug in the bottom. Hole in bottom with rubber plug. Designed specifically for a 9 cm (3.5") size pot.