The external size (4.5 x 3.9 inches) and the internal size (4.25 x 3 inches) are suitable for all vaccination cards. The vaccine card sleeve is made of durable PVC material, which has abrasion and corrosion resistance. With a resealable zipper to keep items drying and protect your vaccination card, it is safe and waterproof. Multi purpose use and reuse for a health record keeper or for special or promotional events, conventions, concerts, festivals, retreats, family & school reunions, fundraisers, field trips, transit bus, VIP Pass and more. Logo could be printed on the lanyard.