Abstract: A thumb-sized tape casette having a rectangular housing with top, bottom and peripheral walls and supply and take-up reels within the housing. A tape member runs between the reels and extends to a tape run parallel to and behind the front peripheral wall. The front wall has a center opening and side openings positioned on either side of the center opening through which the tape run is accessed. Holes in the top and bottom walls are coaxially aligned and are positioned behind the center opening of the front wall. A pair of notches is disposed in the top and bottom walls of the housing on opposite sides of the side openings of the front wall and spaced remotely from the center opening, these notches extending rearwardly into the housing from the front wall in respective parallel planes that are substantially perpendicular to the tape run. Each notch is operative to receive the tape guide that normally is mounted with the transducer of a tape record/reproducing device.