The other difference to note is the fact many 4-track cartridges were produced with see through or transparent cases, whilst 8-track cartridges are not. It is believed this is because a 4-track album release will contain twice as much tape as the equivalent 8-track release, as the album is spilt over 2 programmes and not 4. If buyers could see how little tape was inside some 8-track releases they may feel "short changed" and hence 8-track tapes were not released in see through cases.