From the Duelund site....page on CAST capacitors. Yes mine do say CAST on them....
CAST
Worlds best capacitor
The Duelund CAST Capacitor is our no holds barred flagship capacitor.
The construction builds on the foundation of our Virtual Stack Foil design but does so with the addition of a proprietary WPIO dielectricum which necessitates several days of impregnation under high pressure.
This creates a form with incredible damping properties giving a mechanical stability hitherto unheard of.
On top of this casting process, a ring of hard pressed paper strengthens the damping properties of the design helping music flow effortlessly.
The Duelund CAST capacitor is available for speaker use and as the CAST 630v for DC-applications for size considerations this cap is cylindrical.
Available as pure copper or copper/silver.
Standard sizes 0.001 uF 50 uF other values available on request.
The Duelund CAST Capacitor is considered the worlds best capacitor: