Germs and bacteria are rapidly killed on copper surfaces and copper ions released from the surface have been proposed to play a major role in the killing process. Copper inactivates a variety of pathogens by interacting with oxygen and modifying oxygen molecules. In bacteria, this disrupts the outer layer, damaging the genetic material and cell machinery, which can lead to cell death.
Read the detailed study by American Society for Microbiology here

The protective microbiostatic layer keeps on working and fighting germs as long as it remains in use. The anti-bacterial properties of Copper Patch can last for generations.

Copper, like any other precious metal, develops patina over time. This does not hamper the anti-bacterial properties of copper. The protective microbiostatic layer of the patch will keep on functioning even if it turns darker over time.

Copper is thermo dynamic and absorbs heat and cold very quickly. If your phone tends to heat up while charging (mostly of you charge it overnight) or while being used excessively, we recommend removing the phone cover with Copper Patch to avoid heat absorption by Copper Patch. If your phone does not heat up, you can keep the Copper Patch on throughout!

Copper Patch is super easy to clean. Simply polish with lemon + salt. Wipe off the mixture with a clean damp cloth or rinse off with clean water.