Some popular piano tuning resources: From leading to bottom: a tuning lever, a felt mute, a rubber mute, a felt temperament strip (still left), plus a Papps mute. Prevalent tools for tuning pianos include the tuning lever or "hammer", many different mutes, along with a tuning fork or Digital tuning https://dominickqjznc.topbloghub.com/37200971/fascination-about-piano-repair