G20 Digital GPS Speedometer, Universal Head-Up Display for Cars, Small LED Display Speed MPH Compass Direction, Plug and Play for All Vehicles

Super affordable, looks great, locks on fast and is extremely accurate. officer radar clocked us at 192mph, which is exactly what this meter said. Very responsive, only drawback is it only goes up to 199mph, and when you go 200mph or over it just shows the last two digits, so at 215 mph it’s only displaying 15. But it’s pretty obvious if you just look out the window that you’re doing 215mph not 15mph. Have not exceeded 299mph yet, so don’t know what it does at that point. Maybe this weekend… Will report back.

I don't have the manual but I know there's extra settings. Nice mph works good.

Love it works great

Easy to mount and functions as it should. Accurate speed, bright quality display

I really did not know that GPS could update this fast.This is a simple device, that is so good.I have one car that is very accurate, I used that car along with my phone to calibrate this, and yes you can calibrate it.Then I put it into a car that is not accurate, by knowing how far off the car is, I can now use this to fix a huge problem, and actually know how fast I am driving.Weirdly, most cars do not have accurate speedometers, only police cars have "certified" speedometers, so in most cars you are just guessing, and most GPS is too slow to give useful data.But this device is good, it updates fast, gives great data, is easy to read.Just a useful tool to have if you are dialing in any vehicle, or maybe you are on a vehicle that doesn't have a speedometer and are curious.