The Apple Watch Series 9 is made of various materials, depending on the model. The stainless steel and Hermès versions have a stainless steel case, sapphire crystal, and ceramic back, while the aluminum version has an aluminum case, Ion-X glass, and ceramic back
. The watch is free of harmful substances like beryllium, brominated flame retardants, PVC, phthalates, arsenic in the display glass, and mercury
. The display is made of either Ion-X glass for aluminum cases or sapphire crystal for stainless steel cases
. The watch is also designed to be energy efficient and is made with recycled materials, such as 100% recycled gold in the plating of multiple printed circuit boards
