AKG K872 Master Reference Closed-Back Over-Ear HeadphonesThe K872 Master Reference Closed Back Over Ear Headphones from AKG feature custom 53mm drivers with 1. 5 Tesla magnet systems that deliver precise imaging, deep low frequencies, and extended dynamic range. The optimized closed back design ensures isolation during tracking, mixing and mastering sessions. The open mesh headband and 3D shaped slow retention foam earcups create a personalized fit for good comfort during long sessions. Optimized Closed