OSRAM ORIGINAL P21/5W 12V BAY15d Brake and Parking Light Bulbs, 2-Pack

The OSRAM ORIGINAL P21/5W 12V BAY15d Brake and Parking Light Bulbs are automotive signal lamps designed for rear-light applications. They use a dual-filament configuration to provide separate 21 W and 5 W circuits for brake and tail functions. The 21 W filament activates during braking, while the 5 W filament handles continuous tail or parking light duties. This setup allows a single housing to manage both the brighter stop signal and the dimmer illumination. The components are intended for standard 12 V passenger vehicles. Replacing degraded units with this exact specification restores the intended lighting performance and keeps the vehicle road-compliant.

This package contains two bulbs to allow a complete left and right side replacement. Each unit requires a 12 V electrical system and a compatible BAY15d double-contact bayonet socket for proper installation. A metal base ensures a secure physical connection within the housing and withstands regular thermal cycling. The components are suitable for vehicle owners, workshops, and technicians maintaining standard signal operations. The paired quantity provides convenience for addressing common simultaneous failures on both sides of a vehicle. Confirm the fitment before installing these replacement lamps to ensure correct circuit behaviour.

• P21/5W bulb type – specifies the exact signal lamp format for compatible vehicle housings.
• 21 W and 5 W dual-filament – operates the brake and parking light circuits independently within one unit.
• BAY15d fitting cap – uses a double-contact bayonet base for straightforward mechanical fitment.
• 12 V operating voltage – matches standard automotive electrical systems without requiring adapters.
• 2 bulbs per pack – supplies enough units for a complete axle replacement.
• Metal base construction – supports durable and stable electrical contact in the socket.