Sold individually, this locknut clamp screw with a slotted head fits all Kahler locking nuts and uses a 1/8" allen key, slotted screwdriver or a coin to clamp down through the 9525 Clamp Plate threading into the the base to lock the string.
There are 3 possible clamp screw types to choose from, 8440 is the standard button head with 3/32" allen key drive, 5440 has a cap head with 9/64" allen key drive that has the Floyd style but with the correct threads for Kahler locknuts, and finally, 5441 is 1/8" allen key drive, slotted and can be tightened with a coin.