Put this on my Squire J Mascis Jazzmaster. The look and feel are spot on. The tremolo lock does not function correctly but if you don’t need it to or don’t care it’s a good looking tremolo system. I had read the reviews from others before purchasing so I knew what I was getting into. I like it!

The previous reviews are correct and it appears StewMac simply doesn't care that they are carrying an inferior product. The trem lock is useless as is -- it is completely non functional without significant modification. I also had to do some simple mods to make the trem arm stick.

Just extremely disappointed given that I could have gotten a similarly functioning chinese knockoff for significantly less. I went with StewMac because of their reputation and my satisfaction with previous purchases. This is a huge miss and if StewMac cares about their reputation they'll pull this product.

I was hoping that the older reviews of this were innacurate, but I can report that, yes, in fact the lock isn't functional. You could file away some material to make it work (lengthen the slot towards the tail), but since it's chrome it would probably start flaking.

It's a good trem if you want the "look" of the lock; but unless you're willing to destroy your brand new tremolo it's not worth the purchase.

When I first unpacked this it looked like a good solid unit. However I discovered ( as have other reviewers) that the notch for the locking button is too small, and needed to be enlarged for the lock to function.
Also, the collet/handle arrangement is too loose and lacks any positive engagement mechanism. The collet should be made of better spring steel. On my 67 Jaguar, the handle has a groove that snaps into the collet. This does not, and the handle can fall out.

I was looking to replace my TOM bridge on my jazzmaster and hoped this would give me the ability to enjoy the vibrato arm with added stability.

The quality of the part is great, as expected, although I do hear a lot of spring buzz. I suspect that might be because the TOM posts are bigger than these posts and I have too much space in there not in direct contact with the body. I may have to dowel and redrill, which I was hoping to avoid.

After a bit of research it seems that to properly intonate the low E, you have to cut the screw so it doesn’t hit the string in the pickup side. Easy dremel, but obviously I’ve voided my warranty and return ability.

In the end, this review can serve as a buyer do you homework. Be ready to dowel and redrill in some cases. Be ready to cut the screw to intonate the low E.

StewMac makes great stuff, so if you’re good with this things, you should be a happy camper.

For a machined part costing 50 bucks, I had hoped I wouldn't need to personally alter this trem unit in order for it to function fully and normally. Sadly this is not the case. The slot for the locking mechanism will have to be filed longer in order for the lock to engage. This is something I would have expected from an ultra-cheap Chinese imported unit, but not from StewMac. If you want a fully functional trem unit out of the box, probably better to just buy a Fender branded one until they mitigate the design issues on this one.

Other reviews here state the trem lock does not work. That is not the case, it works fine. The tremolo must be under string tension. In any event, it look great, seems well made and fits well.

Works just as good as the stock fender trem on my blacktop jazzmaster with the addition on the locking button. Lifesaver while playing live.

The screws that adjust string heigh back out of their holes, causing all sorts of trouble.
The string spacing (from middle of the low-E to the middle of the high-E) is more like 57.5
The intonation adjustment screws are directly under the stings, making it a pain to adjust while strings are on there (and what other way would you want to adjust the intonation?).
The tailpiece's tremolo lock slot is too short. Had to file it several mm before it engaged properly.
The tremolo arm falls out very easily.

All of this combined has led me to regret this purchase.

I bought my Squire Jaguar used. It needed a setup really bad. It did not have a locking Tremolo or a Tremolo lever, it must have got lost. I looked at Stewart Mac's version, the price was right and it had everything to bring my Jaguar more like the Fender model. When I received it, the lock didn't seem to look as if it engage, but you have to consider the strings put pressure on the tail to bring it forward. It was O.K. and an improvement over stock Tremolo. The new Tremolo has the outward strings so they are not directly over the screws, which used to break the first string by it's rubbing on that screw. When I showed it to my music instructor she said "it is beautiful". Very happy with this new locking Tremolo, looks great, works great you need one if don't have one.