It is a spike receptacle base of the diameter of 32mm of the Africa ebony used for oboe etc. Or combining PB-10, it places under a speaker, amplifier, etc. and a sound quality improvement can be performed. When a metaled spike is received, in metal, resonance is suppressed and the sound which was clear and became tight by intrusion of a moderate spike is obtained.

External form measure: the diameter 34 mm the height: 12 mm / depth of the form department: 3.5 mm
Material: the African ebony (specific gravity about 1.4)