The CG1000XL is a 100 Percent unit and has a low deck height at 4.5 Inch. Some truck tail gates do not lay flat. They lay tilted up enough that will cause binding when the unit is fully extended. Please check and measure your tailgate before ordering. If the tailgate of your truck is NOT flat, then you have two options. One choice is to install "Tail Gate Drop Down Links" which we sell as an accessory. However some newer trucks do not allow for this modification. The second choice is to install a "Spacer Kit" under the CG1000XL. The "Spacer Kit" is designed to raise the unit high enough to clear a tail gate that does NOT lay perfectly flat.