Teleflex Ammeters - These elegant, top-of-the-line instruments have a distinctive style featuring crisp, clean lettering and perimeter lighting for easy reading, even at night, and vector gauge movement for super accuracy. Tachs and speedos: 3-7/8" dia. bezel; require 3-3/8" dia. hole. Gauges: 2-3/8" dia. bezel; require 2-1/8" dia. hole.