The frequency of the F&D headphones ranges between 20 Hz to 20,000 Hz, while the sensitivity is set at 98 dB/mW. These 'over-the-ear' headphones can be connected to smartphones, laptops and even desktops with the standard 3.5mm jack. So, if you are planning to buy a stylish F&D headphone online from any of the popular online shopping websites like Amazon, Flipkart or Tata Cliq at the cheapest price, you can check out the ones listed here and make the purchase only after you are satisfied with the design and specifications.