Speed boot assembly tool to press the XX boot onto shell.
BTXX is for high-volume cable assemblers. The tool replaces screwing the rear boot on with a motion that pushes the boot over the threads. This destroys the threads in the process, resulting in a firmer application of the boot, with the compromise (acceptable to some, preferable to others, and unacceptable to others still) that the boot can no longer be unscrewed.