This is the little accessory kit for your WD Lifestyle 16.9 fl oz thermal water bottle. It's got three useful pieces: First, a cleaning brush with a wooden handle and natural fibers – super handy for getting into the bottom of the bottle to scrub it clean. Second, a sport & leisure cap with a removable straw. Perfect for when you're on the go or working out; drink through the straw or pop it out and sip from the cap. Third, a universal hook with a snap clip. You can attach this to the bottle and then hook it onto your backpack, belt loop, or gym bag for easy carrying. It's basically all the extras you might want to make your bottle more versatile and easier to maintain. If you love that bottle, this kit just makes it better. Simple as that.