During batting practice, proper sizing holds the Laser Power ST (Exoprecise ROM1 model) for all body shapes/sizes. Exoprecise ROM2 models, bridging the top-half (Exoprecise) to the core/hips (ROM2 Axis Stabilizer), accommodating the simultaneous, lifting of both arms above shoulder-height; the extra support is helpful for players, matching the criteria below, preferring a greater margin for error when sizing:
Deciding, to lift extremely-high; both arms straight and up, using a two-handed follow through.
Female athletes, for example, fastpitch softball players; bigger than a B cup, bra-size.
Extra-small youth players with skinning arms.
Wearing loose and thick sleeves for batting practice, reducing the hold of the ROM1 Stabilizers.