Test and calibration audio cassette tape: 4 in 1. Content: 1. Left / Right channel check 2. Level: 440Hz (0dB ANSI), 2min3. Speed and W&F: 3150Hz (-10dB ANSI),10 min 4. Azimuth: 10kHz (-10dB ANSI),10 min ! Dolby OFF *Genuine Maxell professional tape Type I (120 μs)*This tape was recorded in stereo mode on a reference-tuned Nakamichi deck from digital 192kHz/24bit source. We have different variants of test/calibration tapes.You can find them by clicking this link: "Seller's other items" Dear fans of analog sound! We are glad that our products help you set up your cassette equipment. We enjoy music with you!