The A3SSEA-6AAB-00 is a 3-position maintained selector switch with a cam operator, identified by the description SEL 3POS MAINT CAM E. This is a panel-mount control device used to select and hold one of three operating states in industrial machinery or process lines — typical for mode selection (Auto/Off/Manual) or speed-range selection on a motor drive.
If a direct replacement is required, a parametric search against the 3-position maintained cam switch class is the next step — no pin-compatible drop-in is documented.