Ergonomic (Contoured) Shells
Follow the natural resting shape of the hand to reduce grip tension during a standard mouse-hand orientation, a comfortable middle-ground option most users adapt to immediately without a learning curve.
Vertical Shells
Rotate the hand’s resting angle roughly 90 degrees to reduce forearm pronation, which some users report as more meaningfully reducing strain over long sessions — but requires a short adjustment period that some buyers abandon before feeling the benefit.