LF 125KHz Promixity ID Card Inlay RFID Prelam Sheet is made of 125KHz rfid chip and copper coil antenna with pvc material .It is core part for 125KHz promixity ID cards and semi-products for customer laminating surface material and making into rfid cards . For meeting 125KHz frequency and have to use copper coil antenna with enough turns , standard layout will 5x5 total 25pcs one sheet and customized layout is available .