How much current does this device draw?
Your link for the ET-318 doesn't work, but that doesn't matter. If I have contradicting information like this, what you've been told (by whom?) and what the device actually says, I'd believe the latter.
If the device says ET-318 and the datasheet for the ET-318 says 42 mA, why not believe it? Otherwise you might as well never look at datasheets again.