The McKesson Unna boot is a soft, flexible bandage designed for easy leg wrapping.. The material contains a non-hardening paste of zinc oxide and calamine, applying compression and moisture.. Keeping ulcers moist shortens healing time while calamine soothes.. Each zinc oxide Unna boot bandage comes in a vacuum-seal pouch for easy opening and moisture retention.. Every nonsterile gauze bandage roll is single-use and disposable to reduce cross-contamination.. The cotton and paste are free of latex and preservatives, making the Unna boot with zinc and calamine gentle on sensitive skin..