1,TM card DS1990A-F5 2,unique id number 3,imported stainless steel body 4,water-proof and rust proof TM card DS1990A-F5 is most common one, it has main features as following:Can Be Read in Less Than 5msOperating Voltage Range: 2.8V to 6.0V,Working Temperature Range: -40¡ãC to +85¡ãCimported stainless steel bodywater-proof and rust proof DS1990A/TM1990A iButtons with bracelet