Gretsch Nickel Rocking Bar Bridge with ebony base. I measured 2.024" E to E string spacing. Some folks have asked us for the radius of the bridge top. My 16" radius Stew-Mac gauge seems to be the best fit. Base measures 135.78mm long, 15.69mm deep, around 9.65mm tall at the highest point. Thumb wheels measure 20.07mm diameter. Stud spacing 74mm. Studs and wheels are metric M4 threads. Brand New. Genuine Gretsch 0062844000. UPC 717669292560.