Establishments primarily engaged in packaging, repackaging, and bottling of purchased chemical products, but not engaged in manufacturing chemicals and allied products, are classified in Wholesale or Retail Trade industries.
A phone connector, also known as phone jack, audio jack, headphone jack or jack plug, is a family of electrical connectors typically used for analog audio signals. The phone connector was invented for use in telephone switchboards in the 19th century and is still widely used. The phone connector is cylindrical in shape, with a grooved tip to retain it. In its original audio configuration, it typically has two, three, four and, occasionally, five contacts. Three-contact versions are known as TRS
5 Ways USB Type-C Headphones Will Improve Our Lives. Phone connector, audio jack, TRS, mini, 1/4 inch or 1/8th inch jack. There are a lot of names for the port you use to plug in your headphones. There are many variations and different sizes, but the audio jack has been around in more or less the same form since 1878.