Purpose made for stair housing jigs.  |Ensures tight fit of tread in string. 
Specification:
D=7/8 inch|D=22 mm|C=26 mm|OL=65 mm|A=95 degrees|Shank Diameter=1/2 inch
    
    
    Specification:
D=7/8 inch|D=22 mm|C=26 mm|OL=65 mm|A=95 degrees|Shank Diameter=1/2 inch
        12 months