First – ​Position the plastic collar, threaded side up, above the silicone cup.
Second – ​​Deform the cup into a “C” shape and push it through the collar.
Third – ​Make sure the seal (ie. the top silicone ridge of the cup) sits adjacent to, and completely above, the top of the plastic collar.
Fourth – ​Screw the lid tightly onto the plastic collar to ensure an adequate seal is formed.

We would not advise anyone to put the cup in their bag while it’s filled with a beverage. While liquid in all likelihood would not leak out, there is a chance something inadvertent could occur, and we wouldn’t want your cup to be to blame for a drenched bag. For example, if the stopper were to get snagged on a backpack zipper, it could dislodge, and liquid would spill out of the spout. You should feel completely comfortable collapsing your cup into a disk and throwing it in your bag when it’s mostly clear of liquid though (if some moisture and droplets remain inside the cup, they will not leak out when the cup is properly closed).

Heat transfer through the “naked” silicone cup is similar to the heat transfer you feel through a disposable paper coffee cup without a sleeve. When your coffee or tea is at its hottest, the plastic lid and sleeve let you hold the cup comfortably, with very minimal heat transfer to your hand.

Of course! We use only FDA­ grade polypropylene (#5 recycleable) plastic and LFGB ­certified silicone rubber (LFGB is an EU standard that is considered even more stringent than FDA). We also use no adhesives during assembly.

The cups are manufactured responsibly in China. We share many of the concerns you have about manufacturing the cups there and have ensured the operations involved in manufacturing meet acceptable standards for quality, safety, fair labor, ethical business practices, and environmental responsibility. Our manufacturing and sourcing partner maintains certifications for Quality Management System (ISO 9001) and Environmental Management System (ISO 14001) standards.