1. Brake Pad Wear Sensor Front ABS Wheel Speed Sensor Compatible with E240 E280 E320 E350 E500 E550 W211 S211 2115402017 2. Quality Materials: This electronic front brake pad wear sensor is made of metal and plastic to ensure a long service life under harsh conditions. The sturdy structure resists wear and tear, providing consistent operation over an extended period, with longlasting durability and reliability. Its fast and timely alerts help prevent brake failures, allowing you to enjoy a smooth ride. 3. Function 1: The electronic brake pad wear sensor is a key component that detects brake pad wear and alerts you before replacement is needed. This part ensures timely maintenance, prevents potential brake issues, and achieves performance. By detecting brake pad wear in advance, the sensor contributes to safer driving. 4. Function 2: The brake pad wear indicator sensor is crucial for informing the driver about the condition of the brake pads. The sensor can activate the brake lights to warn vehicles behind and provide functions such as ABS antilock braking system, brake force distribution, internal brake assist, etc., by issuing early warnings about brake pad wear.