This is a small-size 9-track magnetic tape used in early computers. They came in "short" tapes and then in standard size tapes that held more data. Typically they were on the order of 2400 BitsPerInch or 4800 BitsPer Inch, etc. The tape reels could be stored in bulky plastic cases for shipping or smaller "reel lock"s as shown here for storing on racks of tapes stored side by side.