The Sennheiser HD 400 PRO are a pair of open-back headphones designed to give you a completely neutral, pure sound that's perfect for mixing and mastering. As you're working on music, it's important that you hear it as accurately and evenly as possible to get the best sound you can out of it. Enter the HD 400 PRO, the perfect pair of headphones to help you make clear, professional mixes that'll translate naturally to any system. Its comfortable, natural fit and velour earcups make them ideal for long listening sessions, so no matter what you've got to work on, from a big single to a full-length album, you can keep working all day without any discomfort. With sound provided by its custom-designed 120 angled transducers, and a specially developed polymer blend in their diaphragms, the HD 400 PRO are meticulously built to provide clear, accurate sound with absolutely zero distortion at high volumes, improved stereo imaging, and deeper sub-bass that isn't over-emphasised. Precision engineering for precision monitoring. Robust external materials ensure that the HD 400 PRO are a pair of headphones that you can rely on no matter what.