The small Epoxy Resin Transformers are designed with compensation in the Primary winding that guarantees that the output voltage will be fully 120V or fully 240V or whatever at rated Full Load Secondary Amperage. This means that the Transformers will output slightly higher voltage on the Secondary when that winding is not loaded or connected to anything. The percentage varies with design and VA size, but on this Transformer it should be about 4% to 5%. The incoming voltage, if a bit high will also increase the output on a small Transformer.
If the voltage is slightly higher than mentioned, please contact Tech Support for further advice.