Tape cassette

A tape cassette comprising:

• a cassette case having a first end portion and a second end portion separated from the first end portion in a first direction, and having a third end portion and a fourth end portion separated from the third end portion in a second direction;
• a first spool positioned in the cassette case, the first spool positioned closer to the third end portion of the cassette case than to the fourth end portion in the second direction, the first spool positioned closer to the second end portion than to the first end portion in the first direction;
• a ribbon spool rotatable about an axis extending in a third direction, the ribbon spool being positioned in the cassette case, the ribbon spool positioned closer to the fourth end portion than to the third end portion in the second direction, wherein
• the cassette case includes an arm positioned at the first end portion, the arm extending in the second direction, the arm having a first outer surface facing a portion of the cassette case in the first direction and a second outer surface facing away from the cassette case in the first direction, and the arm has an exit configured to allow ink ribbon to be discharged from inside of the cassette case, wherein
• the arm includes a first indicator and a second indicator arranged at the second outer surface in a predetermined pattern, a position of the first indicator is different from a position of the second indicator in the second direction and the third direction.