1. Record inner cover set have 100 pieces plastic record inner sleeves. 2. They are made of PO which is durable. 3. Record cover is about 12 X 12.2 inch, perfect fits for 12 inch record. 4. The record inner cover can be used directly over the record. 5. The round bottom inner record sleeves are long lasting, durable, anti-static, an-ti-dirt, anti-scratch, and very gentle on your records.