Composition: Chip RFID + copper coil Frequency: LF 125KHz or 134.2KHz/HF 13.56MHz Suitable for chips: EM4102, TK4100, M1 S50, FM11RF08, NTAG213, etc Size: custom size, minimum diameter up to 4mm Notice: Tha feum air JavaScript airson an t-susbaint seo.