Professional MC4 Solar Crimping Tool, 1 Year Warranty Certified – ISO9001:2008 Ergonomic ABS handle Precise and compact crimp every time Crimps MC4 Male and Female contacts (25mm2/4mm2/6mm2) The tool will ratchet until adequate crimping force has been applied to the connection The tool features a jaw release override for the instance of incorrect wire placement or a defective terminal To perform the crimp: Strip the cable to expose the cores Crimp each core to the male/female MC4 connectors (as per image 3) Push the connector into the housing until you hear a ""click"" Verify the connector does not easily pull out of the housing Tighten the housing gland until hand tight plus a quarter turn