Dimensions:Length 7.2cm, Breadth 1cm, Height 1cm Material:Zinc alloy, Ferromanganese(Brick & Clip);PE, Fragrance(Aroma Tablets) Instructions: 1. Remove the package and take out the brick, clip. 2. Place the tablets into the back of the brick. 3. Place the magnetic clip on the back of the brick and clip it on the car air conditioning vent. 4. Change tables after 20-40 days, subject to availability.