This is an Ancor double crimp ratchet tool for use with insulated terminals that are non-heat shrink. When crimping an insulated terminal, with a double crimp tool, it is important to note the direction the terminal is place into the crimp nest. The insert end or the end of the terminal which you feed the wire into, should always face the strain relief side of the crimp die.
Remember when I said "double crimp" yes, this tool makes two crimps at the same time. One crimp for the wire and one crimp for strain relief. These two sides of the crimp die are not symmetrical. The side where the colored dot is, on this particular Ancor tool, crimps the strain relief portion of the terminal and the other side crimps the wire end.
If you make a crimp with the wrong side of the crimping tools die, the crimp will not be correct and will likely fail.
TIP: Other double crimp tools from other manufacturers, may be different than this tool. Examine the dies or check with your tool manufacturer for instructions. The side with the smallest crimp ID is the one to crimp the bare wire end.
WARNING: Double crimp tools are UNIDIRECTIONAL! If you crimp the terminal backwards it will pull out far to easily and pose a safety risk. The strain relief crimp nest is considerably larger than the crimp nest designated for the bare wire. A fair number of readers have complained that their double crimp tools don't work well, and some cheap Chinese "look-a-like" tools may not. I always explain that they are unidirectional and the reader most often writes back to say the tool now works just fine.
WARNING: The original Ancor double crimp tool I tested here works admirably well and represented a decent value. Unfortunately, I recently had my hands on a current model of the same tool and it is not the same in terms of performance?
Remember the wire crimp is always the smaller of the two crimp nests and strain relief is always the larger crimp nest.