The german phone code 05248 represents Langenberg, Kreis Gütersloh in Nordrhein-Westfalen.
Note for calls from abroad: In addition to the German country code (+49 or 0049) you can omit the foregoing zero of the dialling code for Langenberg, Kreis Gütersloh. So you can dial +495248... and add the number of the phone line you want to reach.