Intonation - Callaham Compensated Saddles

When the Telecaster was first "designed" and built, the saddles (the metal bar over which the strings pass on their way to the nut.- between the nut and the saddles is where a string vibrates) were two strings to a saddle. Three brass barrels.

You are able to set the overall length of the string via the three spring loaded screws.

Fretted instruments "suffer" with tempered tuning. It's mathematically impossible to lay out the frets in such a way that the strings are in tune over the entire length of the neck. With twenty one to twenty four frets on most electric guitars or scale lengths from twenty four inches to twenty five and three quarters, there is a lot of variation to be had - add into this the curvature (radius) of the fretboard, and you can see there are hurdles to be surmounted.

Back to the Telecaster. The epitome of simple...simplistic. With the three barrel design there is an inherent trade off. One of those two strings will be closer to perfect intonation than the other. Players back in the 1950s learned to bend the spring loaded screws which would angle the barrels...effectively lengthening one string and shortening or retaining the same with the other.

You can see the Tune-O-Matic Bridge design has an individual saddles for each string. The arc described by the radius and scale is also easier to visualize in the arc of the saddles.
Eventually Fender came out of the dark ages and began to install six saddle designs of their own.

But you can also see, this bridge in much harder to adjust. On the TOM there is one spring loaded screw for the string length, and two thumbwheels, one at each end to raise or lower the bridge. With the Fender design, each string is adjusted for intonation and height individually. While that may sound as though it makes for a more perfect instrument, it makes for a colossal pain.
The height adjustment screw are hex heads,  you need two tools instead of one. Each height adjustment is done with two screws - the design itself almost precludes the use of only one. I say almost because someone figured out how to stabilize an offset screw.

My two Teles have three barrel bridges. I like the look. I have no belief in mythical properties of the brass material or the three barrels, themselves, I just like the way they fit the overall old school vibe.
Intonation has always been a huge compromise. And it hurts my ears to hear a guitar that can get no closer to perfect intonation; much as reading text written by the illiterate will hurt my eyes.
(In this way, I am a snob...I guess)

In my own way, I started to do research. I found angled barrels, much the same as the bent screw trick of years gone by. I also found a very clever variation.
A Slanted Compensated Saddle.

The face of each barrel has two surfaces at angles from each other. Length overall is still adjusted with the same spring loaded screws. And dammit, they use hex head screws to adjust the height...one for each string.
After removing the strings it took fifteen minutes to remove the old saddles and replace then with the Callahams. Another ten minutes adjusting intonation and I was done.
Height takes days to dial in. I want the action (height above the fretboard) to be as low as possible. When you lower the action you are inviting fret buzz. So you lower it and play. Find a dead fret...Raise it a bit. Play some more. Determine you can lower it a touch and so on.

The intonation? Spot on. No change in any other quality.
$46 with shipping.