Hi Soo Chee,
I’m sorry for not answering earlier. Axzon is still maintaining this forum. It would be easier to give you a recommendation if you provide more details about your application. With RFID Sensors is important to address all the application details. For example, a sensor that it is going to get exposed to water, depending on the amount of water, will change its read distance.
Finally, please remember that for high volume applications it is possible to design a specific sensor that addresses the application needs.
Regards,
Martin G.