Protect Your Investment and Prevent Disasters: Archival-Quality Mobile Fidelity Sound Lab Record Outer Sleeves Keep Album Jackets in Pristine Condition Widely hailed as the best product of its kind, Mobile Fidelity Sound Lab's Archival Record Sleeves are "clearly" superior. These sturdy, 4-mil thick outer sleeves are made from polypropylene, which makes them more transparent than polyethylene sleeves (which are still available here). Besides providing rock-solid protection from dust, hair, and other debris, these sleeves allow you to enjoy eye-popping album graphics with more clarity. The 4-mil thickness affords stellar archival safekeeping, providing protection against scuffs, wear, denting, dirt, and the moisture that can travel on fingertips. Consistently using these sleeves throughout your collection ensures easy access to LPs on shelves or racks. The sleeves are sized just large enough to provide a close fit while allowing enough room to accommodate gatefold jackets. These sleeves are an absolute necessity for anyone who cares about their vinyl collection. Each pack contains 50 outer sleeves. Put a MoFi outer sleeve on your favorite LP cover, and you'll never be tempted to remove it. The jacket will remain safe, and you'll be able to see the artwork and text clearly. Whether a jacket is in mint condition or slightly worn, this protective outer sleeve will prevent deteriorations in quality. Housing your LP jackets in these strong sleeves provides peace of mind that disasters can be averted ? especially those involving pets or any type of airborne debris.