Poolmaster 23241 1/2oz. OTO Indicator Replacement Solution<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>For maintaining proper water chemistry</li><li>1/2oz. OTO indicator solution</li></ul></div><img src="http://ecx.images-amazon.com/images/I/41RYrybDKwL.jpg" noproxy>