Vision System VS55010 Lane Change ALERT-CAM Chevy / GMC Towing Mirror Set with Blind Spot Safety System Detects when objects enter blind spot and LED flashes to warn driver that an object is approaching; when turn signal is activated, the system beeps to warn the driver when an object approaches blind spot as well Arrow signal for added safety when changing lanes Reliable blind spot technology improves driving safety Warning activation occurs when object is in effective area of both left and right side during driving Original mirrors on the vehicle must be power heated with turn signal in order to use existing power harness and plug