When looking at the properties of:
- Kinematic Viscosity
- Pour Point
- Flash Point
It is look like a standard Naphthenic Type of Oil for Transformer Application
Check NYNAS Product, or any other brand like SHELL Diala Series or MOBILECT series
For top up purpose ensure that the existing oil is compatible with the new purchased one. You can consult the Oil Analysis Lab to do compatibility test prior to top up.
Regards.