Features: This EPA registered copper bird bath cleaner disk naturally purifies water without chemicals, keeping your clean and algae less for up to 20 days. Crafted from 0.6mm thick, 99.99% pure copper with a 3 point support design, this purification disk maximizes water contact for continuous maintenance. Perfect for bird lovers and garden enthusiasts seeking low maintenance solution for outdoor bird baths and backyards water features. Place this weather resistant copper disk in your birdbath to combat green formation while safely coexisting with fountains pumps or heating. Reduce cleaning frequency dramatically from every 3 days to 20 days, while preserving water freshning through natural copper formation. Specifications: Component: Copper Size: Approx.10x10x0.08cm/3.93x3.93x0.03inch Item weight: 40g Package Includes: 1pcs Copper Disc note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you donot mind befores you order. 2.Due to the differences between different monitors, the picture may not reflect the actual color. Thanks for your understandings.