That's the current firmware version installed - first three numbers (3.10) are the version and the last to (.04) relate to the manufacturing date. The latest is 3.11, but the only difference between 3.10 and 3.11 is that 3.11 fixes a bug with the subwoofer trim (setting it to -15dB in 3.10 basically disables the subwoofer trim, producing the equivalent of setting the trim to 0dB).