The first and most obvious suggestion for using towing mirrors is to make sure they’re clean. If you’ve recently had your tow vehicle out on the road, it’s likely a lot of dirt, dust or even mud has found its way onto the mirrors. With dirty mirrors, visibility becomes drastically reduced and increases your chances of causing an accident while turning, backing up or changing lanes.

The size of the mirrors is important — the bigger, the better. The general rule states that for every 10 feet (3 meters) of overall vehicle length (that’s the tow vehicle and the towed vehicle added together), your mirrors should be one inch (2.5 centimeters) in diameter. Therefore, a 50-foot-long (15-meter-long) vehicle should have five-inch (13-centimeter) diameter mirrors attached to it. If you’re worried about hitting or scraping your mirrors in a tight squeeze, you can buy ones that fold back toward the side of the vehicle.

You’ll want to make sure the mirrors aren’t only just wide enough, but also tall enough. The extended width of towing mirrors, especially when they’re angled in slightly toward the vehicle, allow drivers to see greater distances behind them. Towing vehicles are also typically taller than other cars on the road. So the mirrors need to also reflect as much of the ground below the driver as possible. This improves blind spots and additionally increases child safety, since the little ones are often too small to see from inside a truck.

Adjusting your towing mirrors to the correct position is also very important. With the mirrors in a straight position, perpendicular to the vehicle, sit in the driver’s seat and begin by adjusting the left mirror. If you’re able to see 200 feet (61 meters) or more behind the left side of the vehicle, you should be ready. Do the same with the right side, again sitting in the driver’s seat, only this time, you should have someone help you adjust the mirror.