This high-precision wire ferrule crimper features a built-in ratchet that applies correct pressure to ensure a complete crimp every time and the safety release function allows you to stop a faulty crimp before the crimping cycle is complete. The precisely milled, hardened steel dies have individual square crimping slots for each wire size from 10 to 6 AWG. The dies can easily be changed using a slotted screwdriver. The durable ABS grips make this tool comfortable and easy to use.