... and Patrol checkpoint.... RFIF Coin tag is made of ABS material, and produced by ultrasonic plastic welding or filling epoxy ... metal disturbanceKey Features:Dimension: diameter 30, 40, 50mm Housing: ABS, ultrasonic plastic welding; or filling Epoxy Storage temperature: -25 ... to +75 degrees CelsiusOptional ICs:Mifare series ISO14443A, I CODE SLI, ISO 15693, ISO 18000-3, ...