I hike, or I should say that, up until 18 months ago I hiked. These were decent sized hills with 200 to 1,000 foot ascents on relatively steep trails. Then, after losing some cardiac function - and regaining - every hike and even some walks would result in painful trapezius (shoulder) muscles and two muscles in the neck that allow you to hold your head up and turn from side to side. Aside from the pains and aches, it was as though my head weighed 50 pounds. This of course affected my stamina, and my doc finally recommended physical therapy (PT). I hate PT; that's why he held off pushing it. Anyway, PT really worked. I'm hiking again, BUT that doesn't mean that AFTER a 5 mile hike, my shoulders and neck aren't uncomfortable. I'm no spring chicken. Considering that the physical therapist was using deep percussion and regular massage, I asked her what she thought of using a deep tissue massager, showed her the specs for this one, and she said she thought it would be a good adjunct to my twice-a-week PT. This 4290-300 does the trick, and helps with blood flow to those muscles, the lack of which causes much of the weakness and aching. It also just feels good, and much as I hate to turn it off, 10 minutes each side should be max on the shoulders, and 5 minutes each side on the neck. Mobility continues to improve though it should be noted that I also do 10 minutes of neck and shoulder exercises five times a day. So, why four stars? 1. There's an identical Wahl on Amazon (without the model number) that is almost twice as expensive. I spent considerable time trying to find the difference, and finally after getting one answer here (thanks, Evert), I went to Wahl's web site and called them. There is only one "Deep Tissue Percussion Therapeutic Massager." The one for $64 is the same as this. See their chart. 2. It was sent to me in the box that would be displayed in a retail setting (see picture from Wahl on this page), and left on my door step. There was no Amazon packing box. This could have been a restocked item, but it looked pristine inside. 3. I love this vibrator because it has variable settings and 4 heads (see following comparisons). However, since neck muscles are very sensitive, I can't use the "Accupoint Attachment." It "bounces" and it can hurt. I'm not bruised, but I can see how someone could be. It's actually worse at the slowest speed: that's when it actually bounces, and if you apply pressure, it starts dancing all over the place. 4. The "Four Finger Flex Attachment" does not "replicate a human touch massage." Maybe a baby gorilla, but not a human that I would want working on me. If you use this through clothing like a t-shirt, the shirt will start to gather. And if one point dances, four point attachments do the jitterbug. This may be a good thing on your back or calves, but never on your neck. 5. The best has been the "Raised Bump Attachment." For shoulders, I set it at about an 8 (if you think of this going from 0 to 10). For the neck, about a 3 or 4. It isn't what I'd call "gentle," but it ultimately is soothing. At the end of 10 minutes, your shoulders will feel relaxed, and your neck will be able to swivel like a barn owl. Okay, not a barn owl, but you will be able to turn your head without bringing the rest of your torso with you. 6. The "Deep Muscle Attachment" is also the same as "Raised Bump," but I prefer it on my lower back and my brand spanking new hip pointer (which is actually a touch of bursitis in my hip). I may be a mess, but I'm a happier mess with this Wahl. 7. I wish the massager was a little shorter. The unit from top to cord is 16.5 inches. It's fairly comfortable, and does allow you to reach your own lower back although you may contort just enough to make your shoulders ache. It could be a vibrator loop. And it is relatively heavy which is both good and not-so-good. It's good because this has a heavy-duty motor, and it should last years and years. Footnote: When it comes to vibrators of this type, there's probably no name with as long a history as Wahl. My dad had a Wahl that fit over his hand with four springs on top. That was in the 1940s, and we found it 50 years later in his stuff. And yet with all of these great things I have to say, there are just enough annoyances to give it 4 instead of 5 stars. I'll update this review as soon as my knees give way. That could be next week, but I'm rather hoping for no sooner than 2020 when hindsight will bring me back to this writing.