Garden birds can be messy eaters dropping seeds from the feeder which then piles up on your garden below prevent this from happening by adding a seed catcher tray to the underneath of your feeder simply attach the tray to your feeder with the supplied screw available in clear plastic or green metal can be used with the feeder pole not compatible with the niger seed and window feedersr each tray comes complete with a 10 year guarantee for more information click herer diameter 180mm