This set includes 12 TDK Audio Cassette Tapes with a Superior Normal Bias and a capacity of 90 minutes each. The tapes are unopened and come in a jewel case, making them easy to store and protect. The TDK D90 model is compatible with most cassette players and offers a recordable feature for your convenience. With this set, you'll have plenty of tapes to record and store your favorite music, speeches or lectures.