Abstract: A precision peristaltic pump is provided which assures that a precisely controlled length of tubing is operated upon by the pump. Recesses are provided on either side of a tube receiving gap for the pump, which recesses have different sizes and/or shapes and fittings are provided on the tubing on either side of a precisely determined length of tubing, which fittings are sized and/or shaped so as to only fit in one of the recesses in only a single orientation. This assures that the orientation of the tubing in the pump gap is always the same. The fittings may be a block which is formed on the tubing itself and of the same material as the tubing or may include a stop of a harder material, such as a hard plastic, mounted to or sandwiching each block. The pump is designed so that if one of the fittings is not fully seated in the corresponding recess, the projecting fitting interacts with a cover or other element of the pump to prevent the pump from being moved to its operative position.