To shift L type sliding sleeves in a controlled selective manner. Specifications: Run upright to open sleeves and run in the inverted position to close sleeves. NOTE: The Dimension from the bottom of the collet bump to the bottom of the retractor, when tool is assembled, must be precise for the tool to properly function. Measurements: 2 3/8? = 15.69? 2 7/8? = 16.62? 3? = 17.12?