These are "Polyclear" (Polypropylene) Sealable Outer Sleeves for 10" Records. They are approximately 270mm by 264mm with a 32mm flap. (a.k.a. 10-5/8" x 10-3/8" with a 1-1/4" flap) They are perfect for protecting your 10" records and slipcovers from damage. The built in strip makes these sleeves perfect for in store use as you will be able to tell if a customer has tampered with the record. These sleeves are clearer than any comparable thickness sleeve on the market! Perfect for retail stores and displays where you DO NOT want the record routinely opened. Also good for the personal collector to seal up those valuable records you don't want anybody's grubby paws on.