This stacks with the AF hands. This basically makes it to the Puppetmaster can do more then a couple maneuvers without overloading instantly. Its nice to actually not be punished for using a job ability.
@Evilpaul: Please don't link to jkun's testing, his research is very shortsighted and full of errors. Nateypoo has been doing overload/maneuver testing for a long time and has made a wealth of strong posts about it:
Buffon's Collar.... hmmm i think SE is trying to tell us PUP's something but seriously, if its like pup AF hands then you just have to macro this in when you do a maneuver, dont wear this 100%