OPP IOT found industry greatly need a tag that could survive repeated exposures in harsh environment, then,we concentrated on design, develop,manufacture this special RFID tags - PPS Metal UHF RFID Tags OPP6019. The tag are with Protocal EPC class1 Gen2,ISO18000-6C.Frequency :(US)902-928Mhz ,(EU)865-868Mhz, The performance are very good ,which reading distance can reach more than 6M on metal surface. 
And this tag can  resist Acid and alkali ,and also can resist High Temperature,  which can be used  in the harshest of environments,such as used  in construction concrete, Oil and Gas ,outdoor containers , Aerospace, Airline Industry and other harsh industry solutions.