Push or pull solenoid

[kirr45]

Hi guys,

I'm trying to build a lock device but I'm not sure what solenoid I need. I want the lock to be permanently locked, but when I give the controller/solenoid power, I want it to retract so the lock opens. Is this a push or pull solenoid? Basically I want it always extended, then when power is applied, it retracts inside. Then again when I cut power, it extends out again.

[Physics Fu]

It sounds like you want it to pull in, so a pull solenoid?