Seeed grove user interface and control modules seeed studio 113020002 the grove 125khz rfid reader from seeed studio can measure rfid tags within 70mm when using uem4100 cards the reader is supplied with a detachable plug in antenna you can choose between two output formats uart or wiegandseeed provide technical documentation example projects and software libraries on their product pages if you require this information please visit this products page seeed 113020002 grove 125khz