The Schneider Electric ZB4BW085 is a 22 mm light module assembly from the XB4 series, designed as a complete unit comprising the light block, contact block, and fixing collar. It accepts a BA 9s bulb and is supplied via a transformer at either 440 V AC or 480 V AC. The silver alloy (Ag/Ni) contacts are rated for 10 A, with contact code designation A600 Q600 — meaning it's rated for general-use pilot duty on AC and DC control circuits per NEMA standards.
Sourcing reality — obsolete, no direct replacement
This part is officially obsolete per Schneider's lifecycle status. There is no direct successor order code listed, so for an existing XB4 panel with this light module, the sourcing path is through surplus or broker channels. If you're holding a BOM line for this code, the practical move is to verify the installed base and source a critical spare before the existing unit fails — one in the cabinet is the only insurance here.
The 22 mm mounting diameter is the standard panel cutout for XB4 operators — it fits any XB4 enclosure or blanking plate. The BA 9s bulb base means you're sourcing a specific miniature bayonet bulb, not the more common BA 7s or wedge-base LEDs. The 440/480 V AC supply via transformer tells you this module is intended for direct connection to a control transformer secondary, not a 24 V DC pilot light circuit. The 10 A contact rating is for the built-in contact block, which switches the indicator load, not a power circuit.