I had trouble with the first waterer I ordered, because the blue plastic perch/reservoir just would not screw onto the glass water container. However, I contacted Duncraft and they immediately sent me a new complete set, which works just as it should. I hung it in a small tree near our window feeder, and the chickadees, titmice and goldfinches have been using it regularly. So far I haven't seen larger birds use it, such as cardinals, but time will tell about their acceptance of it. I've very happy with this product. It can not be used in the winter in colder climates, however, because the glass will no doubt crack the the water freezes.