Usually 3-5 Days. 45 Day Lowest Price - 100% Satisfaction Guarantee. The Proline.650 daily proves its worldwide achievement in music production, in recording studios, at the microphone, and in television and broadcasting studios. The high-class gold plated transducers are very sensitive and provide a maximum of transparency. The complete isolation of a closed back headphone with the honest sound of open headphones makes it ideal professional studio usage.