Dual Indicators: Internal and External. This will facilitate confirming all 3 parameters of sterilization: time, temperature and presence of steam. Chemi-Vapor or Steam autoclave, and Ethylene Oxide sterilization. Made of strong, medical grade sterilization paper. Built in large color changing indicators. Wide Self Sealing adhesive tape. Perforated Fold helps form an airtight seal for storage. Easy Opening thumb notch on every pouch. Secure seal for protection on possible tearing of sharp instruments. See through tinted plastic for strong puncture resistance and easy view of instruments. Sealed corners help prevent curling and collection of any contaminates.