This is an Intellitec battery disconnect relay that latches. The latching is a mechanical addition to the standard relay where the energizing force either attracts and activates or repels and deactivates a stop or latch to keep the relay closed without the need for power. The only problem with this design is that the return spring is very thin and compressible and can weaken over time especially with rv/boat storage heat which can allow the relay to essentially close on its own when it is supposed to be open. Staying open requires the return spring to have enough force to keep the copper plunger plate away from the copper load contacts. To fix this you can take the relay apart and carefully stretch the return spring beyond its elastic limit making it naturally longer at rest. This makes it apply more force when compressed and it will do its job better inside the relay keeping the contacts apart.