Used to keep the swimming pool clean by releasing copper and other minerals into the swimming pool. The chlorine-free solar shock replacement copper anode is a secret mixture of metals that kill microorganisms and prevents the growth of metals in the pool. Replacing copper anodes can help you save 80% of your chlorine costs. Suitable for Solar Pool Ionizer Purifier Chlorine Free Purifiers Type: Copper Anode for Solar Pool Ionizer Purifier Installation: Vertical Purifying Position: Terminal Purification Water Quality Requirements: Municipal Water/Well Water colour:Copper color Material:Copper alloy size:1.8 x 10.5cm Package Contents: 4 x Copper Anode Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.