Feature-wise, the basic and most standard thing to remember in a GPS is, your unit must contain, WAAS or the (Wide Area Augmentation System) this type of feature will help you increase the accuracy of your unit to map out your location and decided on a route, and another feature that you would want to have in your GPS is the Channel, since Global Positioning System runs on satellite signals, the more signals you are able to access the more accurate and reliable the information you will receive.