SKU                                                     Size Range                              Best for:

SP4_12CPP & SP4F12CPP                318 mm to 322 mm               Older 1960 to mid 80's singles and smaller gate-fold albums

SP4_12.75CPP &  SP4F12.75CPP     324 mm to 328 mm              Newer "small & medium" gate-folds. Some larger Mofi, Blue Notes, Craft, etc may not fit.

SP4_13CPP                                          328 mm to 332 mm              Very large gate-folds (doubles and   triple album) large Mofi, Blue Notes, etc...