Product Name:RFID Metal Labels Type:ess R O or R W Operating Frequency:LF(125KHz) or HF (13.56MHz) Size:Dia.20mm, thickness:3mm Reading Distance:Up to 8cm Material:Epoxy Special Magnetic Material Operating Temperature:-40 ~ 80 (Celsius) Storage Temperature:-40 ~ 100 (Celsius) Reading & Writing Time:100, 000 times Feature:Waterproof