You can enjoy the birds up-close and from the comfort of inside your home. The new feeders sit on the windowsill and are held in place by easy to use spring-set dowels that fit securely in the screen window tracks. The Mirrored WIndowsill Feeders uses a one-way mirror panel that allows you to see the birds up-close and they can't see you. The Windowsill Feeders have an open back and acrylic top that allows you lots of great viewing. Both feeders have a perforated metal screen platform for seed and can be filled and cleaned from inside your home. Our windowsill feeders are easy to install, easy to clean and fill. Feeder fit windows up to 38" wide and are made from western red cedar.