Observer Window Feeder. UV stabilized polycarbonate- won't yellow with age, dependably durable Sloped cover- overhangs dish and prevents runoff of rain into dish Open construction- clear view of birds on the feeder 3 high quality suction cups- hold feeder securely. WARNING This product can expose you to chemicals including Bisphenol A (BPA), which is known to the State of California to cause birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.