shaped to fit into the pin holes, smooth the saw cuts, 

and define the string "ramp" at the front of each hole. 

They're available in two  gauges; the smallest (.028"/0.7mm) 

works for unwound strings. 

and a wider 0.051 (1.3mm)

The cutting edge is 76mm long and is slightly rounded 

to cut a slot with a radiussed bottom so the string won't bind in the slot.

 Overall length 150mm. 

Made of chrome alloy steel.

add the file set for fettling purposes

Diamond file set

a 1mm and a 1.5mm round diamond file 40mm long

with a 3mm shank, a tapered file tapering from 0.6mm to 1.5mm over 32mm

 and a wooden handle

Purple handle diamond file which tapers

from 0.6mm to 1.6mm over about 60mm