Tetra ReptoGuard Water Conditioner Block， 12-Count (4 Packs with 3 Blocks per Pack)</br></br><div style="text-align:left"><b>[Product Information]</b><br><ul><li>12-Count (4 Packs with 3 Blocks per Pack) Tetra ReptoGuard Water Conditioner Blocks，</li><li>Protect Your Pet From A Variety of Disease-Causing Organisms</li><li>Each turtle-shaped block treats up to 20-Gallon</li><li>Value Pack of 12 Blocks!</li></ul></div></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br><img src='http://ecx.images-amazon.com/images/I/51Xlj%2BD5Q0L.jpg' noproxy></br>