Solid Material: Made of real cattle bone, provide more exquisite tone than plastic. More convenient to install: These Guitar bone saddles and nuts have pre-cut Guitar string slots, more quick and convenient to install. Real cattle bone: The tiny porosity and high density provide better intonation and clarity, let you enjoy in the vivide music. Universal Size: Top Nut size: 43x6x9mm, Bone Saddle size: 72x3x9mm, compatible with most Acoustic guitar. More fast customer service reaction: We are stiving to immprove our customer service, if you hanve any problem with this item ,please feel free to ask us via the email. Specification: Bone nut size:43x6x9mm Bone Saddle size: 72x3x9mm Material: cattle bone Package list: Bone nut*2 Bone Saddle*2