Nature2 Express Mineral Cartridge Replacement for Pool Sanitizers<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>For above-ground or in-ground pools up to 25，000 gallons</li><li>Easy， do-it-yourself installation， everything in one box</li><li>Superior water quality with lower chlorine requirements</li><li>Controlled Release Technology (CRT) ensures optimal mineral levels</li><li>GUARANTEED， Kills bacteria， controls algae， won’t stain</li><li>Replacement mineral cartridge for all Express units</li><li>Destroys bacteria and controls algae using natural minerals</li></ul></div><img src="http://ecx.images-amazon.com/images/I/31-nN%2BOOkLL.jpg" noproxy>