Consider the mode of transportation. You can get seat belt extenders for almost any type of transportation, but certain extenders work with specific seat belt types. For example, a manufacturer may specialize in seat belt extenders for airplanes, while another company may make extenders for cars.
Find out what organization certifies the seat belt extender. Some companies will post a disclaimer on their products indicating you assume all risk involved in using a seat belt extender. Other companies provide information indicating the organization approving of the product. For example, the Federal Aviation Administration (FAA) certifies seat belt extenders designed for airplanes after the product passes an inspection process. For cars, look for Federal Motor Vehicle Safety Standards approval.
Determine the connection method for the seat belt extender. Some click into the seat belt holder, but others require mounting the extender to the frame of the vehicle. Check the fitting for the seat belt extender before you purchase it. Some universal extenders only work with vehicles manufactured after 2002.
Compare the length of seat belt extenders. To find the length you need in order to buckle the seat belt, you can extend the regular belt to its full capacity and measure the distance between the buckle on the belt and the holder. You need at least that much length to make an extender work for you, so make sure you pick one with enough length to help the situation.
Look for extenders that keep the seat belt in the correct position, especially when you need a seat belt extender for a car. In a seat with an extender, the shoulder strap should hit your body in the correct position in order to offer the most protection.
Match the color of the extender to your regular seat belts. It's harder to see an extender when it's the same color as your regular belt, making the device less obvious. Most seat belts come in standard colors, and many seat belt extender manufacturers work to match them.
