Base measures 135.55mm long, 15.53mm deep, around 7.79mm tall at the thickest point. This base fits Rocking Bar and Space Control bridges. Thumb wheels 20mm ( I measured 20.06mm) diameter. Stud spacing center to center 74mm (I measured 74.09mm). Thumb wheels and studs are metric M4 threads. Brand New. Genuine Gretsch 0080625000. UPC 717669893651.