Wooffy T. Wooffy announces the measurement result via acoustic signals. Wooffy T. shows you the battery level both acoustically and tactually, ie via vibrations, making it ideal for deafblind users. All commercially available 1.5V and 9V block batteries and rechargeable batteries can be tested. The handling of Wooffy and Wooffy T is quite simple, you do not even have to worry about the correct polarity of the batteries under test. Just hold the battery to the contacts - and you'll get the result! Wooffy requires two, easily replaceable 1.5V AAA / micro batteries. He is small and slim and fits easily into your shirt or trouser pocket. You can even wear it with a drawstring around the neck.