Sunny took this compass from his dead friend's hand when he was a little boy(s01e01). Somehow he saved it through all the years. It was stored inside a box in his house near the barrack. It had a middle layer bearing the same design as MK's pendant: a city with radiating lights. Later he discovered that the pages inside the book from Minerva had a burnt hole that fit the compass perfectly, and once inside the burnt hole the compass started working. It was not clear what the compass pointed to.