The first of this range was the Sennheiser HD480 type headphone with 1700 ohm capsules. In order to distinguish these headphones from standard non-protected versions, they are distinctively marked. Limiting level is fixed at 93dB (note 1). Standard connector options are available, and because the limiter is within the capsule, it is possible to use spare or replacement leads, as for standard versions.

All types (except coiled cables which are tinsel wire) utilise steel cables for longer life (unlike standard HD480’s which have copper cables). As with in-line limiters, each headphone is individually calibrated, and as each capsule has its own individually calibrated limiter, spare limited capsules are available.

Single-sided cables connect to the left earpiece, with a loop over the headband to the right earpiece; a fixing kit is supplied to hold the cable onto the headband. Note that in these versions, the earpieces are mounted onto the headband the opposite way up (connector at the top).
The headphones are available as standard in thirteen terminated versions: