This is my version of the ben 10 omnitrix from Alien force.

NO SCREWS NEEDED. Only glue used. 

I used the model from Vinsil_Props. I modified the core as I felt it wasn't stable enough for kids. I also used another wrist strap design as I felt it was better.

I plan to make this better by allowing the buttons to work in the future to pop up the core. I also plan to add a watch latch for easy application