An overtravel stop will arrest the motion of the trigger just after the break, and prevent movement. Over travel is not always considered bad by some, as the force of the trigger finger does not impact on the gun directly after sear release. Improving the trigger pull An adjustable trigger may have ways to adjust all of these stages, plus trigger location. For example, a first stage or takeup adjustment might include weight and travel, a second stage or sear engagement adjustment might include weight and travel, and a trigger stop adjustment would limit the overtravel. While adjustable triggers may provide the greatest level of control, much can be done with standard non-adjustable triggers. Careful hand fitting and polishing of parts, addition of high precision or adjustable aftermarket parts, or fabrication of new parts can greatly improve most triggers. Care should be taken, however, since trigger work requires a great deal of care and precision, and a bad trigger job can easily render a firearm highly unsafe or unusable. Liability issues Most manufacturers ship firearms with fairly heavy, nonadjustable triggers, colloquially known as lawyer triggers. This is out of concern for liability; firearms are inherently dangerous, and allowing the user to adjust the trigger, or even implying such adjustments can be made, exposes the manufacturer to lawsuit. Likewise, manufacturers of aftermarket parts expose themselves to similar liability issues. Sights A firearm's sights help its user to align the barrel with an intended target. In some cases the only refinement in a "target" firearm over a standard model is improved sights. Adjustable sights are essential for most target shooting, as they allow compensation for variables such as target range and ammunition type. Firearms with non-adjustable or coarsely adjustable sights cannot give their holders the ability to reliably shoot on target in changing conditions. Improvements in visibility and sharpness of a target image provided by some sights can also improve users' aim and consistency. Typical open sights with a blade, post or bead near the muzzle and a notch over the breech are good for quick alignment but far from ideal for accuracy. An aperture sight mounted closer to the user's eye and farther from the front sight tightens accuracy by lengthening the sight radius while helping the person take better advantage of the improvement. Some of these "peep sights" provide precise, repeatable adjustments for long range shooting with no need for