Our "Knuddel Buddel" is a popular classic and highly appreciated by our customers for the positive properties of virgin wool. Virgin wool not only retains heat very well, but also releases it evenly. Whether for treating yourself or as a gift, the Knuddel Buddel is highly recommended. The cover is white-natural colored, and you can choose the color of the hot water bottle depending on availability. The cover, handcrafted by us, is made of 100% virgin wool on a cotton (80%) and polyamide (20%) fabric backing. The fabric itself is certified Standard 100 by OEKO-TEX. Please wash the cover exclusively by hand and only with a wool detergent. The cover does not need to be removed to fill the hot water bottle. However, please never fill boiling water into the hot water bottle, as you could scald yourself. Please also pay attention to the warning notices, which you can find both on the hot water bottle itself and further down in this description.