there are several youtube videos that show you how to set these up and fine tune them for your desired application
584341
I have two of these units and let me be the first to tell you that the instructions leave a lot to be desired.  That being said, there are several youtube videos that show you how to set these up and fine tune them for your desired application.  Once you run through them a couple of times and get use to the interface it's not that difficult.  So far it has functioned as expected and for under $20 its easily replaced.
1647027
<div id="video-block-R33W5CZQQVP04C" class="a-section a-spacing-small a-spacing-top-mini video-block"></div><input type="hidden" name="" value="https://images-na.ssl-images-amazon.com/images/I/B1Ax0iCQo4S.mp4" class="video-url"><input type="hidden" name="" value="https://images-na.ssl-images-amazon.com/images/I/91Z9qWD6DTS.png" class="video-slate-img-url">&nbsp;&nbsp;First off, these are great channels. They work well with my LED strip. They look great and do a great job diffusing the light. The plastic cover is easy to take off, easy to put on and very secure. These come with clips that you can use to fasten to whatever surface you plan on using it on.

The reason I am giving this only 4 stars instead of 5 is because it didn't come with hardware to fasten the clips. There are some fasteners that clip on to the channels, but no screws for the fasteners. Another way you could potentially fasten these channels is with double sided tape, but it does not come with that either. Basically, once you get these, you will need to go to the store again to find a way to fasten them to whatever you want to use them for.

There are also no instructions. You should be able to figure out how to install it yourself but if not, you are out of luck.

(Note: I received these in exchange for an honest review.)
1753376
Difficult to install, but if you watch their youtube video on installation and take your time, your efforts are definitely rewarded.
2002825
Product was great.  Look for how to on YouTube before getting started or purchasing to make sure you know what you are getting into.  Not too difficult if you prepare and follow instructions closely.
2365635
It's good stuff if u know what r u doing ..!
Just watch the video on you tube couple time and it's easy as 1 2 3.
4668299
These hit hard, just have to figure out how to tune them right:P using mtx thunder 500 1 amp, would love if someone can help me tune this setup.
1533679
a bit pricey but worth every penny once you get the hang of it video comes out looking clean and smooth
3349918
Not sure how to use these.... they have a video tutorial for how to place them on. but who has time for that.?
2844119
Not as great as they make them out to be. Watch some ytube videos.
1428241
I had to watch a couple of youtube clips to help me get them programed how I wanted to use them.  But after that they are great, the lapel mics work awesome!
1920224
Had to watch a video to figure out how to set it up.  But one view on YOUTUBE and it was a piece of cake.
1859526
I bought these tuners to go with a neck that I purchased from the same seller. These tuners are very nice. Yes you have bushings to install and to do that there are a few ways to do this. DO NOT HAMMER THESE IN!!! BAD things happen when you do this. So do NOT install them this way. a smart person will check the bushing against the hole first. On this installation I had to slightly ream the holes out then test the fit. The very tip of the bushing should just try to slip in. Now the fun part. you can take a bolt with 2 flat washers and a nut and then use that to install by simply tightening it all up and this will press the bushing in with even pressure all the way around. Use some tape on the bushing and on the back of the head stock so you don't mar the wood. Once the bushing is seated then loosen the nut and remove the bolt from the hole and do this. Set one ot the tuners in and make sure this is lined up as if it were already installed and mark your four screw holes. do this for each tuner . Next is to drill pilot holes for each of the four screws and do that for all the screw holes on each tuner. Then put the tuners on and screw them to the head stock. Take your time one by one till all the tuners are installed. I hope you removed the tape before you did all this. Once those bad boys are installed apply a little bit of white lithium grease to the worm gear and turn the keys a few times to make sure they are properly lubed and it does not take that much to lube these up. Just a tiny bit will work. Then you are ready to string up your bass and tune up and play. These tuners are really nice and they do the job.
2667974
lots of really good videos on YouTube explaining the nuances of the program and how best to set up and use.
396596
For the price it's worth it 200%.
If you follow the directions and be patient toward watching some youtube videos on how to use this product, you will get a good result.
1494617
These are fine, they work as expected.  I advise buyers to view the youtube video that the company provides us with the website before installing so, you can get good results the first application.  I did and everything worked out well the first time.
2306277
http://youtu.be/s15yWLZVRJY?list=UUgjAyPLf6ZvhJF1vw5ZkBkQ
watch my video review
167444
Set up is key. You have to know what you're doing with a bit like this!