These are 12" super heavyweight paper inner sleeves. Use these to replace your old worn and torn vinyl record inner sleeves and help keep the vinyl clean! The sleeves measure 12-1/8" x 12" (307.97mm x 304.8mm) and are made of 29# paper. Perfect for cleaning up ones personal collection of written on, stained, and ripped up sleeves - or for replacing on vinyl you're trying to sell!