The A3SSCD-6AAB-00 is a 3-position selector switch with left-right-spring return action, cam operated — the kind of panel-mounted control you'd find on a machine control station or transfer line for mode selection or jog-forward/off/jog-reverse. The spring return means it snaps back to center when released, so it's suited for momentary commands where the operator shouldn't leave the machine in a run state unattended. Lifecycle stage is flagged as eol_hot — the manufacturer has ended production. This part is no longer in active manufacture, so new-build BOMs should look at current-series alternatives.
What the description tells you about fit
"SEL 3POS LR-SPRINGRTN CAM C" decodes as: SEL brand, 3 positions, left-right spring return, cam operated, and the 'C' indicates the contact configuration or cam code. Verify the cam code on the existing unit for correct contact sequencing.