Chain length is also a consideration as some length of chain could conceivably upward wrapped around a bird's neck throughout a vigorous play session. My youngest son was related a horrific accident when another driver clipped his car causing him to spin across two lanes of freeway (I-35 near Buda). https://Directory5.org/The-Benefit-Of-Having-A-Bird-Bath-And-A-Feeder-With-Your-Yard_346213.html