The pad’s rubber lip fits over the earcup groove and behind the retaining ring; rotate into place.
Sound / ANC
Beyerdynamic lists these as the original DT 1770 PRO MKI options. The headphone was supplied with velour and leatherette pads, which Beyerdynamic describes as producing different sound characteristics.
Beyerdynamic’s guide separately lists black velour and black artificial-leather replacement pads for DT 1770 PRO MKI and separate acoustic-disc pad sets for MKII. It also describes the DT 1770 pad mounting procedure.