Rheem 46-22863-04 Transformer has a built in fuse protection to stop future transformers from shorting out.
Primary Power: 120 Volts.
Secondary Power:24 Volts.
Volt Amps:40VA
Max fuse: 2 Amps
Replaces: 46-22863-04, 46-22691-01, 46-22691-02, 46-22691-03, 46-22698-01, 46-22863-01, 46-22863-02, 46-22865-01, 46-24124-03, 46-24124-05, 46-25107-05, and 46-22863-04