I dont know that exact push pin, but if it is still attached to the box part the other end goes on the push pin. So when it is at rest a little pressure is on the spring and as you push onthe pin the spring is getting tighter,and when you remove your finger the spring will spring will pull it back to the original rest position. I would think there would be a little hook or eye visible on the push pin,but once again just a guess, if all else fails just post a pic of it.