The Atomic LED bulb delivers unbeatable brightness that stands in a league of its own. CAN bus compatible and suitable for both 12V and 24V systems, it’s a powerful, plug-and-play upgrade for indicators, brake lights, or reverse lights. Boasting an Incredible 1500 lumens. The Atomic 1157 is Built for performance, reliability, and maximum visibility.
Feature
1157 (BAY15D)
1156 (BA15S) / BAU15S
Pin Position
180° apart (straight across)
180° (BA15S) / 150° (BAU15S)
Contact Type
Dual contact (2 filaments)
Single contact
Base Diameter
15 mm
15 mm
Socket Fit
Dual-function bayonet
Single-function bayonet
The 1157 has two electrical contacts at the base and two filaments, allowing it to perform two brightness levels—ideal for brake + tail or turn + running light combos.
Bulb Type
Filaments
Common Use Cases
1157
2
Brake + tail lights, turn + DRL
1156
1
Reverse lights, single-function signals
BAU15S
1
Amber turn signals
1157 bulbs are often used where a light needs to switch between dim and bright modes, like tail lights that brighten when braking.
Not interchangeable with 1156 or BAU15S due to different contact configuration and socket design.
Even though they share the same diameter, the dual-contact base of the 1157 won't work in a single-contact socket.
