There are two threaded plastic. So far (about 1 month in use) there were no problems. Otherwise, the closure can be bought.
When cleaning it should be noted that the bottle is not suitable for the dishwasher. For cleaning there by Sigg, a brush and cleaning tablets. I use only hot water and a sponge brush, making it possible to the bottle (also thanks to the large opening) cleaned.
According to the manual one should not pour hot drinks. Juice and shower set for the bottle no problem. (I fill a tepid (warm up pretty) tea and has so far not notice any damage.)
I already have a 1l bottle. One should remember that the 1.5 l bottles but some is even greater.
