These are vintage styled telecaster bridges with one very useful innovation - instead of having three brass barrel saddles, they have six. Having one for each string instead of sharing a barrel between two is an incredibly useful change, as it allows you to set up the intonation of your guitar perfectly.
The intonation of a guitar is typically adjusted by moving the bridge saddles towards or away from the nut (the other end where the string is anchored), in so doing, the length of vibrating string is changed - making the frets of the instrument fall at different points. Having incorrect intonation can literally mean that your instrument is out of tune while it's in perfect tune! The notes will go progressively more out of tune as you work your way up the neck. If you want a Telecaster that is always in perfect tune all over the neck, these bridges are the way to go.
Mounting hole spacing: 64mm