The A3SLDC-6AAB-91 is a 30 mm panel-mount selector switch with a lever handle that gives you a maintained left position and a momentary right position — spring-return to center when released. It carries a 1NO/NC contact block rated for 10 A, sized for control-circuit switching in industrial enclosures.
The 10 A rating covers the contact block's continuous carry and switching capacity for pilot-duty and low-power control loads. The 30 mm panel cutout is the standard North American heavy-duty hole size; it fits the same footprint as Allen-Bradley 800T/H and similar 30 mm operators. The 3-position logic — maintained left, momentary right — is a common pattern for jog-forward / run-reverse or hand-off-auto stations. The momentary right side means the switch returns to center when released, so it suits inch or test modes where the operator must hold the handle to keep the circuit closed.