Adapters with spare speakers for the screw fixing supports used in aeronautical headsets type StarCom10 / 12 - HD1000 / 1200 - David Clark and similar.
Impedance 300 ohms. Solder contacts.
The adapters are 3D resin printed and fit perfectly into old speaker stands.
No screws are included.
The red dot identifies the positive pole.
Sicily, Italy 