Antibacterial balls for AS-9000 shower model.
The antibacterial balls in the shower filter soften the water and neutralize any bacteria. The result is clean water that is kind to skin and hair. In theory, the balls are forever. Their effect is based on the movement of the balls and the water. The rolling stone does not moss. Over time, they may accumulate colour and start to smell, at which point you may want to replace them.