Read Only 125KHz Paper LF TK4100 RFID Sticker is 125KHz rfid technology with optional paper or flexible pvc or pet top material . TK4100 will fully compatible with EM4100 and 64 bits memory read only since EM4100 has off-production for many years . The 125KHz rfid sticker will be created for some curved surface objects' identification ,considering the 125KHz frequency will be enough and this kind of rfid sticker has to use copper coil antenna with chipset so it will not pretty flat surface and will embossing little for antenna path marks .With optional 3M or nomal adhesive backside .