This part is no longer available from Allen Organ. Allen wants you to spend hundreds of dollars on a new replacement board. $15 may seem a lot for a small ferrite tuning slug with tuning knob 	but we have spent considerable time and $ in order to provide a suitable replacement. This is the tuning control used on the MOS  clock board. Also included are instructions for removing the original slug if broken and how to tune the organ. You will need 	either a tuning fork or a low cost piano tuning box to re-tune the clock frequency. We use a frequency counter or a Korg tuner.