These are new 12" (2 mil. thick!) premium plastic resealable oversize outer sleeves! [13-7/8" x 13-1/4" + 1-5/8" flap or 352mm x 337mm + 41mm flap)] These oversized archival quality crystal clear sleeves are a great choice for protecting your precious record box sets. The special adhesive used on this sleeve allows you to open & reseal the records many times, keeping your vinyl box sets safe and dust-free. Biaxially Oriented Polypropylene (BOPP) means a much better sleeve clarity than the traditional cast polypropylene or polyethylene. Made by Long Term Record Supply Professionals