Match wedge shafts to full and partial swings
The fitter would use an X100 shaft in the gap wedge because it is still used for full swings and very few partials. For the sand and lob wedges, which are used almost exclusively for soft shots, the shaft setup is treated differently.
Channel: Club Champion
Watch official source at 21:45Why this context matters
The shaft models are specific to the player, but the full-swing versus soft-shot distinction is explicit.