The 91531-1 is a CERTI-CRIMP II straight action Hand Tool for use with AMP tandem spring 26 to 22AWG contacts. The tool features a fixed die (crimper), a movable die (anvil), a locator/insulation stop and a ratchet. The insulation adjustment knob is used to regulate the crimp height of the contact insulation barrel during the crimping operation. The locator/insulation stop positions the contact and limits the insertion distance of the stripped wire into the contact. In use, the locator/insulation stop rests in the locator slot of the contact. The ratchet assures full crimping of the contact. Once engaged, the ratchet will not release until the dies have been fully closed.