25pk – Manufacturing facility Direct Bulk Packed Audio Cassettes. Really useful for recording or duplicating of track, spoken phrase, instructional, educational or spiritual methods. Kind I Customary Bias Audio Cassette. 75 Mins (overall time), 37:30 Mins (in step with aspect); Minimal: 25pk. BULK MEANS: NO CASSETTE BOX , NO CASSETTE LABELS, JUST A PLAIN CLEAR CASSETTE TAPE.