This high quality mealworm feeder is a great addition to your bird-feeding set up. Whilst it won't stop cheeky squirrels from trying their best to steal the contents, the metal tube is designed to at least make it a great deal harder for them. The metal feed tube is approximately 22cm tall and 8cm across, giving a fillable volume of roughly 1.1 litres. The lid unscrews for filling and the perch tray at the base unscrews for easy cleaning. The diameter of each feeding hole is roughly 6mm so the feeder can be used for nuts as well.