Complex sentence: The entry level model SRH240, studio use SRH440, professional monitoring SRH840, and the SRH750DJ, all of which are closed-back designs that do not offer noise cancellation.
Split into simpler sentences: The entry level model SRH240, a studio SRH440, a professional monitoring SRH840 and finally the SRH750DJ. All of which are closed-back designs and do not offer noise cancellation.