The only good thing is they're cheap
After that, you get what you pay for. The balls don'thold together very well, and there were a lot of crumbling balls in the box. These are useless when using a feeder.
Also they're in those green nets. THESE ARE DANGEROUS FOR BIRDS! They can easily become tangled in them, and conservation organisations have been advising against them for years. Also, these add to plastic waste - I'd guess anyone feeding wild birds is interested in conservation, so don't want to add to plastic pollution.