I measure 10.8 ohms resistance of the incandescent bulb but only read 128 mA current draw when putting across a 12.8V wheelchair battery. Apparently the resistance of the filament bulb can increase 10 fold when current runs through it and it heats up. The bulb is plenty bright enough and for $5, the tester seems to be of better than expected quality and the cord seems pretty thick and strong. As the resistance of the bulb depends on the voltage applied, I would expect that using on lower voltages will draw more current than expected if this matters for your application.

All went well, although, associate was a bit grumpy when cashing me out.

It works and is simple to use but the light is not very bright for outside fence testing

Heavy duty compared to other testers I have had. Nice heavy ground cord.