TESLA manufactures a wide range of distribution transformers ranging from 25 KVA to 5000 KVA with all voltage class and upto 33 KV.These transformers can be free breathing, fitted with a conservator or hermetically sealed. The liquid filled range can be cooled by either tank - mounted plate radiators or by corrugations on the side of their tanks. The latter being known as conventional type transformer.Free breathing units, with or without conservator are normally oil-filled, while hermetically sealed transformers can be filled with either oil or one of several low flammability synthetic fluids. Both types can be supplied with HV and LV Switchgear and incorporated into substations.

Hermetically sealed transformers are totally maintenance free and are particularly suited for use in exposed outdoor environments such as moisture, salt or dust laden atmospheres. They are used extensively in chemical plants, oil and gas terminals where poor accessibility makes regular maintenance impracticable. Transformers immersed in synthetic coolants are suitable for use indoors with adequate ventilation or near to the load center where oil would not be considered environmentally acceptable.