Holds current Post Card Sizes from 4x6 to Standard 4.25x6 2 mil ultra clear polypropylene Polypropylene is an inert, archival quality, PVC-Free material Ideal protections against dust and moisture during handling and storage 100 per pack Guardhouse Shield#: 636836681085. Size: 4 3/8 x 6 1/8. Color: Clear. Sold in Packs of 100. Case Qty: 10000 .