The A3L4AA-6LLR is a red LED indicator light from the A3 series, rated for 6-24V supply. It's the kind of panel-mount pilot light you'd see on a control cabinet door or an operator station, giving a clear red status signal across a wide voltage range.
Sourcing now runs through independent distribution and surplus channels. No guarantee of sustained supply; if your line needs a long-term fit, this is the moment to evaluate a cross-reference.