The product is low frequency RFID product. They're 134.2KHz and 125KHz.There have two colors you can choose, yellow and pink. Read range is about 50cm.It used to trace the process of growth of animal. It designed as an earring to avoid animal to begnaw it because their curiosity. Then, it can assure the using life of the tag. It produced as the totally safe materials, non-toxic, durability. Functions of Ear tags are anti feces, anti urine, resistance to temperature shock, waterproof, thermo stability and low-temperature resistance, and resistance to acid and alkali. Storage temperature: -40℃~80℃