Package Includes: (4) Beyerdynamic DT-150-250 Ultra-High Isolation Live/Broadcast/Studio Headphones(1) Mackie HM-400 Pro Rackmount 4-Channel Headphone Amplifier w/12 Headphone outputsAuthorized Beyerdynamic Dealer! Description of DT-150-250: The DT 150 is a closed dynamic studio headphone with a modular construction offering excellent ambient noise isolation. The powerful neodymium magnet system provides high-fidelity reproduction and a balanced sound. The headband and earphone cushioning systems have been carefully designed for maximum comfort and serviceability. The padded headband can adjusted to fit on every head. Features: Beyerdynamic DT 150 Closed Monitoring Headphones For Use In Loud environments broadcast film and recording studios Closed headphone Excellent ambient noise attenuation Powerful neodymium headphone system for excellent reproduction accuracy Wide frequency response (5 - 30.000 Hz) Capable of handling very high SPL Rugged easy serviceable construction as all parts are replaceable Single-sided detachable cable Circumaural ear pads Excellent comfort for long-term wearing Details: Transmission type Wired Headphone design (operating principle) Closed Headphone impedance 250 ohms Headphone frequency response 5 - 30.000 Hz Nominal sound pressure level 97 dB Construction Circumaural (around the ear) Cable & plug Straight connecting cable with mini-jack plug (3.5 mm) & ¼“ adapter (6.35 mm) Net weight without packaging 388 g Click Here To View The Specification Sheet (Link Opens In A New Tab) Click Here To View The User Manual (Link Opens In A New Tab)Advantages of purchasing from an authorized seller: Best prices - We sell all Beyerdynamic Products at the lowest price as possible. Full Factory Warranty Detailed information of all products Lifetime Customer Service by Beyerdynamic Product Experts Guaranteed legitimate and authentic merchandise Please note: If you purchase Beyerdynamic from an un-authorized seller then you are taking a big risk. You will not have any manufacturers warranty and there is no guarantee that the item is authentic brand new or even working.Authorized MackieDealer Description of HM-400: The 19” rackmount HM-400 4-ChannelHeadphone Amplifier offers an incredible amount of versatility andexcellent sound quality in a single rack space. Perfect for professionalapplications including studios Houses of Worship practice spaces andmore. The HM-400 features a main input with level control plus stereoouts aux inputs and EQ per channel with 12 total headphone outputs. Features: Mackie HM-400 Pro Rack-Mount 4-Channel HeadphoneAmplifier with 12 Headphone Outputs L/R Main stereo inputs plus L/R stereo outputs