The tree nest swing is built with heavy duty steel frame and premium polypropylene made swing seat. Polypropylene is a very durable plastic that is resistant to fatigue and has good impact strength. Commonly used in trampoline mat.The ropes are securely con-nected to the frame by a patented system.It can be easily assembled and adusted in height.We manufacture 300 thousands of nest swings for Lidl and Aldi every year.EU, GS and US ASTM approved