✔ Inner Diameter: The Inner fitting measures about 16mm in diameter, suitable for PVC pipe or metal pipe with outer diameter of 16mm. ✔ Plastic Material: Made of plastic material, the fitting is able to withstand impact, not easy to crack or break. ✔ 5 Types: right angle 3-way connector / right angle 4-way connector / right angle 5-way connector / two-dimensional 3-way connector / two-dimensional 4-way connector. ✔ Wide Application: Muti- choose to meet your various greenhouse construction needs, suitable for flower stands and greenhouse frames construction and so . ✔ Stable Support: The connector can stably support your greenhouse, which is not easily blown down in windy or rainy weathers.