MUCH QUIETER THAN TRADITIONAL CLIPPERS, FITS LITTLE HEADS WELL!
We got this for our 4 year old son.  He doesn't have any sensory issues, so I can't speak to that.  We got it because, since he was old enough to talk, he told us he wanted his hair as short as possible.  Nothing 'spikey'.  For about a year we cut his hair with my husband's adult sized clippers.  While those worked OK, I always had to go over his head again with scissors and cut all of the stray hairs that were missed on his tiny head.  While this does still miss some hairs (nothing is perfect), it does a much better job of fitting his child-sized head and only leaves a few stragglers behind.<br /><br />So far I've used the 2 shortest settings and they both look comparable to the length you'd get in a barber shop.<br /><br />It's much quieter than the other clippers we have, though it still does make a low buzzing noise.  It's quiet enough that we can have the TV on normal volume and still hear it while cutting his hair.<br /><br />It has an easy to use on/off switch.<br /><br />I've never tested its waterproof ability.<br /><br />The package comes with several different lengths of guards, a charger, an apron, and it's supposed to come with a cleaning brush (though ours wasn't in the package).  The charger is a USB, not a standard plug.  I'm sure everyone has access to a USB charging port in 2017, but it's worth noting it's not a traditional US outlet plug.<br /><br />For the price this is great.  I'm sure if I spent a ton of money I'd never have to use scissors to clean up missed hairs, but this is totally worth it for our needs!
Rating: 4 stars