It is a pinpoint base of the diameter of 41mm of the Africa ebony used for oboe etc. Or combining PB-21, it places under a speaker, amplifier, etc. and a sound quality improvement can be performed. The effect that specific gravity tightens sound by the pinpoint support effect for 1.4 and the strong, very heavy quality of the material becomes large. The height of 21mm and a spike part of the height of a main part is 5mm. Although it is of the same type as PB-9, since size is large, the stability at the time of installation increases.

External form measure: the diameter 41 mm the height: 21 mm /the height of the pin department: 5 mm
Material: the African ebony (specific gravity about 1.4)