One issue is standards. There are well-developed standards for low- and high-frequency RFID systems, but most companies want to use UHF in the supply chain because it offers longer read range—up to 20 feet under good conditions. UHF technology is relatively new, and standards weren't established until recently. Another issue is cost. RFID readers typically cost $1,000 or more. Companies would need thousands of readers to cover all their factories, warehouses and stores. RFID tags are also fairly expensive—20 cents or more—which makes them impractical for identifying millions of items that cost only a few dollars.