This is an autographed card sleeve from 1990 by WEA (catalog number 171190.2). It features signatures of 5 members on the front, making it a unique collectible for fans of Boom Crash Opera.
To use this card sleeve, simply place your card inside to protect it. When handling, make sure your hands are clean to avoid getting dirt or fingerprints on the sleeve or the signatures. Store it in a cool, dry place away from direct sunlight to prevent fading of the signatures. If it gets dirty, gently wipe it with a soft, dry cloth. Don't use any harsh chemicals or abrasive materials as they may damage the sleeve or the autographs.
