Tin foil hat radio with a metal bucket. The AM radio is completely inside a metal enclosure. This leads to a noticeable reduction in signal strength received by the AM radio. The efficiency of a metal enclosure in blocking electromagnetic radiation depends on the thickness of the foil, as dictated by the "skin depth" of the conductor for a particular wave frequency range of the radiation. For half-millimetre-thick aluminum foil, radiation above about 20 kHz (i.e., including both AM and FM bands) would be partially blocked, although aluminum foil is not sold in this thickness, so numerous layers of foil would be required
What Love Is Made Of it in "Little Red" (2014). Upon its release, "What Love Is Made Of" received generally favorable reviews from contemporary music journalists, who favored the composition and Katy's distinctive vocal performance. It peaked at number 21 on the UK Singles Chart, and entered three other charts, reaching the top 40. To promote the song, Katy performed it live at the BBC Radio 1Xtra Live special and at her headline set during the Wireless Festival. Emil Nava also filmed and directed a music video for the song which was deemed similar to film series "The Fast and the Furious". In April 2011,