Jacknuts are similar to a nutsert in the fact that they are a one-sided fastener the provides an anchorpoint for fasteners but they are not pulled with a tool. Jacknuts are pulled when the fastener is tightened and the four "legs" collapse onto the inside of the mounting surface, holding it in place. Jacknuts are not as strong or permanent as nutserts. Grip range is the amount of material the jacknut will be going through, not the actual length of the jacknut, which will always be longer thn the grip range.