The Aven Tools 10178 Crimping Tool is a high-precision wire ferrule crimper with a built-in ratchet that applies correct pressure to ensure a complete crimp every time. The crimper features a safety release function that 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 22 to 12 AWG. The dies can be easily changed using a slotted screwdriver. The durable ABS grips make the crimper comfortable and easy to use.