These are typically used for the inner saddles A-D-G-B and are US thread, allen key head for USA-made vintage tremolos.
They will not fit into metric-threaded saddles typically found on guitars manufactured in Japan, Korea or China.
Fitting the correct height adjustment screws can eliminate the uncomfortable scratchy effect if the screws are too long, of course this was not originally a problem because there was a cover to the bridge but soon that was removed by players to help palm muting.
Specification:
(exc. 20% VAT)
