Universal size fits ALL wide mouth bottles.  Made from flexible silicone the Universal Splashguard has enough flex to conform to the size variations of different brands' wide mouth bottles.  The SplashGuard is an insert which provides a smaller drinking hole, blocks the splash, is easily removed for cleaning and is dishwasher safe.  Allows for easy filling without removing the SplashGuard.  Look for more vibrant colors rolling out in 2012.