These are 45rpm black 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 heavy-weight 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 are what we use in our own retail store! (These go over the naked vinyl record and slide into a jacket or outer sleeve.)