works great but needs extra care to prevent failure [SEP] ok same complaint as everyone else my first unit died in less than months from water seepage into the battery and switch compartments that being said it does an excellent job of brushing your teeth it is cheaper than the sealed battery sonicaire and when the battery dies you do not have to wait for it to recharge just pop in new batteries i use nimh rechargeables so the downside is that you have to dry the unit carefully after each use i still cannot find out how the water is getting inside the unit but it is irrelevant if you dry it well enough do not bother with trying to seal the unit it is more trouble than it is worth my current unit is a year old and working fine btw save the battery cap from any old dead units i dropped my new one and the battery cap broke i used the cap from the dead unit cleaned off the corrosion and it worked fineso at least i got some utility out of the dead onesigh minus one star for stupid design flaw