This is a curtain model hideaway license plate. Every set has 2 license plates, plate A and plate B. There are 3 buttons (A, B and AB) on the remote controller and main unit, Press A/B button once, the A/B curtain will roll down to cover the license plate number, press again A/B, the curtain will roll up and show the license plate number. If press AB button once, you can control the two plate at the same time. There is an LED indicator show the condition of the license plate curtain status.