The original Inertials with updated materials and manufacturing technology... the models that started it all.

SL-581F Hi-Moment Offset
191g Tungsten blend - heel and toe weighting
SL-582F Hi Moment Non-Offset
206g Tungsten blend - heel and toe weighting
SL-583F New Moment
182g Tungsten blend - heel and toe weighting
SL-584F Center Stroke Mallet
132g Tungsten blend - extreme back, heel and toe weighting