Two Columbia Records single-sided 12″ acetates of three of Mason’s popular singles, each disc featuring versions of ‘So High,’ ‘Let It Go, Let It Flow,’ and ‘Mystic Traveller,’ one disc labeled “EQ’d” and the other labeled “Flat.” Both are identified in type on The Mastering Lab labels with relevant track listings and artist info. In overall fine condition. Both accompanied by their original sleeves from The Mastering Lab (one sleeve affected by a coffee mug stain). Originates from the personal collection of legendary engineer and producer Ron Nevison. RR Auction COA.