Oatey 25605 Hercules 6-Ounce White Tube Plumber's Caulk Siliconized acrylic-latex plumber's caulk. Flows easily, does not harden in tube or cartridge, will not crumble, resists shrinkage. Flexible, durable, extremely mildew-resistant, waterproof. Flows easily, does not harden in tube or cartridge, will not crumble, resists shrinkage Silicon zed acrylic-latex plumber's caulk Flexible, durable, extremely mildew-resistant, waterproof