EI 28 Transformer Feature:
ups3 EI Model AVR Power Transformer with Over-current, Over-voltage and Over-heating Protections

EI 28 transformer features:

Insulation: class F and H Input voltage: 155 to 310V Output voltage: custom design Over-current, voltage and over-heating protections Power: 100VA to 3kVA Frequency: 50/60Hz Dimension: EI28 to 190