Diode 70's symbol

[nonost]

 Hi guys. Does anyone know about this kind of diode?



It's the amp power section of an old amp from the 70's by the german brand Dual. In the manual it is listed as Stabilizing Diode ZE2. In its body it says 2.1V BTW.

Is it just a Zener?

Well, hope you all are doing good. Lockdown sucks.

Cheers.

[mug]

This may be it, but you need to register to see the full datasheet...
https://www.radiomuseum.org/tubes/tube_ze2.html