I’m holding that identical item right this moment. This particular see-through card is for demonstration purposes, a functional prop for sales and demonstrations. It’s a dual-technology card. The 125kHz Prox (with the more substantial inner antenna) is the classsic Prox, while the 13.56MHz (sparser outer antenna) is the more secure iClass.
This kind of card is used for physical access control. Each antenna has its own “chip” and the chips are set up to have the same encoded id and facility code. Why have two credential technologies in one card? Because as companies or campuses grow, instead of removing and replacing the older (less secure) Prox reader heads, organizations instead opt to just add iClass readers as they grow. Prox readers get moved to less security sensitive doors.
Neither Prox nor iClass are NFC tags, but many multi-technology readers can read Prox, iClass and NFC tags
