Mercedes-Benz recalled more than 42,000 vehicles because they may be missing a gauge to monitor the condition of rear brake pads.

The inspection gauge that checks the wear of the rear brake pads may not be present in some 2019-2021 models. Furthermore, the owner's manual may not include instructions on how to use the inspection gauge, according to an NHTSA report.

These abnormalities in the vehicle do not comply with the requirements of Federal Motor Vehicle Safety Standard number 135, "Light Vehicle Brake Systems," NHTSA said.

Vehicles that do not have an inspection gauge that measures the wear of the brake pads will not show worn brake pads, which could increase the possibility of a crash.

The recall affects certain vehicles in the following models:

• 2019-2020 A220
• 2020 CLA250
• 2020 AMG A35
• 2020 AMG CLA45
• 2020 AMG CLA35
• 2020 GLB250
• 2021 GLA250

Last week's recalls:Toyota, Ford, and Jeep among 2.1 million vehicles recalled

How will Mercedes-Benz fix the problem?

Dealers will install vehicles needing an inspection gauge and an owner manual with information about the gauge at no cost.

Customers can call Mercedes-Benz customer service at 1-800-367-6372 if they have any questions.