Struthers-Dunn’s 255BXBPM-120A is a dual coil latching plug-in relay.

 

Struthers-Dunn - Dual Coil latching plug-in relay

The 255 Series is a two coil latching version of the general purpose type 219 relay. When the
operate coil is momentarily energized, the energized position with the power removed from the
coil. The second coil when momentarily energized, provides electrical reset of the contacts. All
contacts operate from a common armature to prevent contact overlapping. Coils are rated for
continuous duty.

Source: Struthers-Dunn