These are 45rpm paper inner sleeves with a hole. The inner sleeves measure 7-1/8" x 7" (or 181mm x 178mm). The sleeves feature a 1/4" lip between the front and the back for easy machine insertion. The sleeves have square corners and are made from heavyweight paper (29#). These sleeves are archival quality: acid free, and alkaline free! Replace your worn out or torn inner sleeves and freshen up your collection. These go over the naked vinyl record and slide into a jacket or outer sleeve.