【RFID Chip】:Using the original T5577 chip with a frequency of 125kHz, it can easily replicate TK4100 (EM4100)/EM4305 smart cards. 【Ring Material】:It is made by dropping epoxy resin into the zirconia ceramic outer shell, with elegant appearance and smart chips. You can take it anywhere. 【Ring Size】:Sizes determined according to US standards: US #6, #7, #8, #9, #10, #11, #12 【USE CASE】:TK4100 (EM4100)/EM4305 erasable replication ID smart card and other 125kHz frequencies. 【PRODUCT ADVANTAGES】:Ceramic materials give the ring a unique texture and durability. Epoxy resin enhances the shine and stability of the ring. The combination of ceramic and epoxy resin significantly improves its hardness and wear resistance, which makes the ring particularly sturdy and scratch-resistant.