Sennheiser HD 650 Open Back Audiophile Headphones with Detachable Cable (Used)Condition: Used Like New Condition Details: Fully functional with no visible wear; original packaging included (may show light handling). These open back, dynamic circumaural headphones are built for accurate audio reproduction. Acoustic silk is used to provide uniform attenuation across the ear cups, supporting consistent sound output. Lightweight aluminum voice coils improve transient response, while full range drivers deliver a frequency response