Pool Controls - Stabiliser, commonly known as “sunscreen”, is made up of Cyanuric Acid (CYA) and it creates a chemical bond with a pool's chlorine to protect it from the sun's UV
Summer Fun Chlorine Stabiliser 1 kg : Amazon.de: Garden
HTH Easiflo Briquettes 25Kg
Chlorine Stabilizer 2lb - Water Balancers - The Great Escape
2kg Protec Chlorine Stabiliser | The Pool Shop Group