The size of any FingerTips™ Finger Placement Guide is based on the "vibrating string length" of the particular size and type of instrument.

To find this vibrating string length on your instrument, simply measure any string from the nut, (the ridge at the end of the fingerboard next to the peg box,) to the bridge (the arched, slotted piece that holds the strings away from the body of the instrument). See illustration below. Once you have the proper vibrating string length, find the corresponding FingerTips™ guide for your instrument here.