Disregard other reviews
This model works as well as or better than an earlier one for which I bought this as a replacement (the older battery would no longer hold a charge). The length control works perfectly well (I don't know why some referred to unexpected changes in that regard. It does not change unless you choose to do so). Some complained about the noise level. No, it won't make you deaf--it will just remind you of the need for recharging.
Rating: 4 stars