EMS Semi-Tone Lever Silver - 2 Prong - pressed steel harp semi-tone lever suitable for EMS 19 String Pixie Harp, EMS 22 String Heather Harp, EMS 29 String Minstrel Harp and others. 

Available as a single prong semi-tone  lever (1 prong) suitable for the treble strings (first 12) or double prong semi-tone  lever (2 prong) suitable for the bass strings