Telex Discovery headset is a model Discovery-i. The order number
on the box is 300107-420 and was a special build made for the
Department of Defense. These headsets are brand new in the boxes.
A flexible comfort sling on the underside of the headband contours
to the user's head, and evenly distributes the weight of the
headphone. Speaker type is Dynamic Mono, impedance 150 ohms with
a noise cancelling dynamic boom microphone. The cord end is shown
below and can easily be replaced with 1/4", mini-plug or
4-pin XLR connector.