Amtrans AMCY Series Aluminum foil, Paper-in-Oil 0.22UF 630V Capacitors, made in Japan.
They have an outer shell in enclosed in insulating plastic over a brass tube.
The Capacitor is held solidly inside the tube with a Special Epoxy Resin, black in color, to reduce the external vibration effecting the sound.
The leadouts are 0.8mm diameter gold plated OFC copper.
The outer foil is clearly marked and should be connected to the lowest impedance path to ground. For example this end should be furthest away from the anode of a Tube/ Valve.
Please see photos for measurement.
Bought New, used less than 30 hours for a DIY prototype, no longer needed.