Made of 100% untreated Merino wool, which means it is ultra-breathable and ultra-soft. For all of you out there who are afraid of using wool-don’t worry, this wool is not scratchy! Very comfortable for baby; keeps cool during the summer and warm during the winter. We can say that this wool pull-on is virtually leak proof and is excellent for using at nighttime. The Tiny Tush is really a miracle! The natural lanolin in the wool neutralizes the urine odors and only has to be hand-washed once a week, or when soiled. Use this with the Tiny Tush one sized diaper…highly recommended! Hand wash/air dry. Made in USA.