The Sennheiser HD 300 PROtect are closed-back over-ear studio monitor headphones offering high-resolution audio reproduction and switchable peak level protection for musicians, audio engineers, and event staff in broadcast, studio, and live stage applications. The precision-diaphragm dynamic drivers produce a wide frequency response of 6 Hz to 25 kHz with low distortion and a maximum SPL of 123 dB. The HD 300 PROtect's circumaural closed-back design provides up to 32 dB of passive isolation from ambient noise. A 1/4" TRS adapter is included to allow easy connectivity with mixers, dedicated headphone amplifiers, and audio interfaces. The HD 300 PROtect headphones fold for compact storage and transport. Switchable Active Gard technology attenuates signals above 110 dB down to a safe level while maintaining clear, distortion-free sound.