Bang & Olufsen ( B&O, OMX : BO B ) is a Danish company that designs and manufactures audio products, television sets and telephones. It was founded in 1925 by Peter Bang and Svend Olufsen, whose first significant product was a radio that worked with alternating current, when most radios were run from batteries. In 2004, the company opened a factory in the Czech Republic where it employs approximately 250 staff producing mainly audio products.