The Regulating Rack with Template Set provides the profile of a grand piano's strings along the strike line. 
Select sizes from The Template Set to match the sections of a grand action and fix them to the rail so their lower edges represent strike.

Spanning the entire action, the Regulating Rack either hugs the sides of the keyframe on a workbench or rides in tracks on a Custom Keybed (in a Regulation Station Deluxe). LED lights in the rail illuminate both templates and hammers (comes with ac-dc adapter and 6' dc cable extension).