Is very well made. Fit right on my Epiphone Les Paul with no surgery required. Essentially, this is a Bigsby type tremolo. It is not intended for aggressive use. It is intended for a warble tremolo effect. Exactly what Mr. Bigsby and Mr. Fender intended. I hear people complaining it does not dive bomb or do all these tricks. That is because it is not a Floyd Rose. If you use it like a Floyd- expect to tune it every song just like Hendrix did with his Strat. Or doing all kinds of set up tricks EVH did and still didn't work- until he got his Floyd Rose he was plagued with tuning. Same with Randy Rhoads. So don't trash the product when you really don't know what you're saying. Mr Fender and Mr. Bigsby had no idea of hard rock and heavy metal when they did tremolos.

This trem has a very smooth operation. Completely adjustable. No adverse changes in tone. I did note that on a Les Paul- when you shorten the length of the bar, it interferes with your playing hand.

I advise using a roller bridge. That helps a lot with tuning. There is a bundle option on here that offers both. The roller bridge is excellent

Just like a Fender or Bigsby, you have to pay serious attention to breaking the strings in. Again- some people comment while not knowing what they are talking about. If you install strings and go to town on this thing- you're going to be disappointed. If you get your EVH on- you're going to be disappointed. The nut on your guitar needs to be lubricated and adjusted/filed so that no catching of the strings happens. If you have a standard bridge the saddles need lubed. You have to stretch the strings in like crazy. All of that is just the nature of the beast. Keep in mind locking tuners don't really help- especially if your nut is Fffed up. They are locking tuners- not a Floyd Rose locking nut. They make string changes faster. That's about it.

Really solid craftsmanship, thick, machined metal. Really smooth motion very impressed! Worth, every penny. Helped me finish out this custom build- looks and sounds great and holds tune well with my rolling bridge. My only constructive criticism is that the vibrato arm could be just a teeny tiny bit tighter where it fastens. I use a pretty heavy hand, and there was a slight noise from the small amount of play in the arm housing. It should be easy to fix this at home, and overall, I'm really excited about the idea of using this in future builds.

I like this so far, but a lot of tweaking was required. I had to return the first one because the arm locknut kept loosening after a few minutes of use. The replacement is working fine so far.
I use .0095's on my Epiphone SG. The large center Allen screw on top can be used to center the bar as it has a good amount of play. If the string retainer is clicking against the plate, tune to pitch ,loosen the top screw, then tighten. Playing around with this will help adjust. When centered, it provides about one tone of pull-up and a little more on the dive.
Make sure your nut is dressed to reduce string binding and remove sharp edges on bridge saddles. Also, make sure all saddles are facing the same direction,with the angled edge facing toward the vibrato. Last resort, try a roller bridge( but can suck some sustain.)
The string retainer slots have sharp edges that were breaking my high e and b strings, so you need to break the sharps. Also, I replaced the spring with a Reverend soft touch Bigsby spring that makes for a looser feel and more fun to use. My guitar is staying in tune very well even with constant whammy use.
Very good and would purchase again.

I installed this tonight on a Tokai SG and it fit perfectly. I read a pot of feedback about this and a few issues I read in the comments or saw on YouTube have been addressed.

1. Spring power. I have read comments that the spring is too strong and too weak. Mine came with 2 springs. The lighter spring is installed and works great with 9s. If I were using heavier strings I might use the bigger spring.

2. It comes with a felt pad to protect the guitar and provide a better fit on archtops.

3. Some of the sharp edges that have caused string breakage have been rounded. I don't see anything that looks like it's going to damage my strings.

I installed with a roller bridge, and locking tuners. I kept the existing nut and decided not to add a string butler because I didn't want to encourage neck dive, and it works really well. It definitely took a few hours of playing with new strings for it to settle in, but now it seems to be very stable. All in all, would definitely recommend this.

I don't have experience with the vibrato unit this is a copy of, so this may not apply to the Duesenberg/Goldo vibrato units. The Guyker unit I recieved from Amazon was not returning to pitch and it was breaking high E strings at the string gromet. The isssue is there is a lot of side to side play as you actuate the vibrato. The string achcor bar will move toward and then away from the low E string during use. I disassembled my unit did some measuring and found some M2.5 flat washers on Amazon. I ordered those and installed them on the retainer bar to the high E side of the stanchions. This took all the side to side play out of the unit and it now returns to pitch consistenly and its stopped eating High E strings. Hope this helps for folks having return to pitch or sting break issues.